Communication method and related apparatus

Abstract

Embodiments of the present application provide a communication method and a related apparatus. In the method, when a preset condition is satisfied, a terminal device sends a first message, wherein the first message is used for requesting to establish an Internet protocol (IP) multimedia subsystem (IMS) public data network (PDN) connection. On one hand, the preset condition for the terminal device to establish the IMS PDN connection is defined. On the other hand, by defining that the preset condition is related to a geostationary earth orbit (GEO), a decision that certain terminal devices explicitly establish the IMS PDN connection in a GEO scenario can be made. Alternatively, by defining that the preset condition is related to a special terminal (for example, a terminal supporting transmitting an IMS service by means of the Internet of Things (LoT), a terminal supporting at least one data radio bearer (DRB), or a terminal receiving first indication information), establishment of an unnecessary IMS PDN connection by a non-special terminal can be reduced.

Description

A communication method and related apparatus

[0001] This application claims priority to Chinese Patent Application No. 202510128736.5, filed with the State Intellectual Property Office of China on January 27, 2025, entitled "A Communication Method and Related Device", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of communication technology, and in particular to a communication method and related apparatus. Background Technology

[0003] Terminal devices can make calls via the Internet Protocol (IP) Multimedia Subsystem (IMS). For example, in a 5G system, the terminal device first registers with the network and establishes an IMS Protocol Data Unit (PDU) session to carry voice data and signaling. The PDU session establishment process establishes a user plane connection between the terminal device and IMS. Afterward, the terminal device initiates IMS signaling interaction with IMS through the established IMS PDU session, including 1) IMS registration, such as to complete service authorization; and 2) an IMS call process to call the called terminal device. During this process, the establishment of a GBR QoS flow is triggered for voice data transmission. A similar process occurs in 4G systems. The differences from 5G are: 1) In 4G, the user plane connection carrying voice data and signaling is called a PDN connection, and the corresponding PDN connection establishment process corresponds to the PDU session establishment process in 5G; 2) the GBR QoS flow is called a dedicated bearer. In addition, in 4G, a PDN connection can be established during the attachment process of the terminal device.

[0004] However, with the introduction of diverse terminal devices, such as smart terminals, handheld terminals, and Internet of Things (IoT) terminals, some terminals may be limited by factors such as terminal capabilities and may not require the transmission of IMS services. Summary of the Invention

[0005] This application provides a communication method and related apparatus. Under preset conditions, a terminal device requests to establish an IMS public data network (PDN) connection. On one hand, the preset conditions for establishing an IMS PDN connection can be defined. On the other hand, the preset conditions can be related to geostationary earth orbit (GEO), for example, the terminal device establishes an IMS PDN connection in a GEO environment. Alternatively, the preset conditions can be related to specific terminals, for example, reducing the need for non-specific terminals to establish unnecessary IMS PDN connections.

[0006] This application provides a communication method, which is executed by a terminal, or by a component of the terminal (e.g., a processor, chip, or chip system), or by a logic module or software capable of implementing all or part of the terminal's functions. In this first aspect and its possible implementations, the method is described as being executed by a terminal device. In this method, if preset conditions are met, the terminal device sends a first message requesting the establishment of an Internet Protocol Multimedia Subsystem Public Data Network (IMS PDN) connection. The terminal device receives a second message indicating whether the establishment of the IMS PDN connection is permitted.

[0007] The preset conditions include one or more of the following: the terminal device accesses via GEO, the terminal device supports accessing IMS services via GEO, the terminal device supports transmitting IMS services via the Internet of Things (IoT), the terminal device receives a first indication message from the network device, or the terminal device supports at least one data radio bearer (DRB), and the first indication message is used to indicate that an IMS PDN connection can be established.

[0008] Optionally, the terminal device sends a first message to the network device. Correspondingly, the terminal device receives a second message sent by the network device.

[0009] Based on the above scheme, under the condition that preset conditions are met, the terminal device sends a first message, which is used by the terminal device or network device to establish an IMS PDN connection. On the one hand, the preset conditions for establishing an IMS PDN connection by the terminal device are defined. On the other hand, by limiting the preset conditions to be related to GEO, the decision to establish an IMS PDN connection for certain terminal devices in GEO scenarios can be explicitly made. For example, the preset conditions may include one or more of the following: the terminal device accesses via GEO, or the terminal device supports accessing IMS services via GEO. Alternatively, by limiting the preset conditions to be related to specific terminals (e.g., terminals that support IMS service transmission via IoT, terminals that support at least one DRB, or terminals that have received the first indication information), unnecessary IMS PDN connections established by non-specific terminals can be reduced.

[0010] Optionally, in one possible implementation of the first aspect, the first message is also used to indicate at least one of the following: the terminal device supports accessing IMS services via GEO access, the terminal device supports implementing IMS services via IoT transmission, or the terminal device supports at least one DRB.

[0011] In this possible implementation, the information related to GEO, IoT, or DRB indicated by the first message can provide a basis for the network device to send the second message. Alternatively, the information indicated by the first message can be used by the network device to determine whether to allow or authorize the terminal device to establish an IMS PDN connection, or in other words, it can be used by the network device to determine whether to establish an IMS PDN connection. Here, the IMS PDN connection can be described as an IMS PDN connection accessed via or based on GEO.

[0012] Optionally, in one possible implementation of the first aspect, the first message is used to carry the IMS access point name (APN).

[0013] In this possible implementation, the first message may also specifically carry the IMS APN, so that the network device can determine the APN requested by the terminal device based on the IMS APN.

[0014] Optionally, in one possible implementation of the first aspect, the second message includes second indication information, which is used to indicate that access to IMS services via GEO access is not permitted.

[0015] In this possible implementation, the terminal device receives an indication that access to IMS services via GEO is not permitted, and therefore no longer requests to establish an IMS PDN connection when accessing via GEO.

[0016] Optionally, in one possible implementation of the first aspect, the terminal device may not transmit IMS services, or in other words, it may not transmit IMS services when accessing via GEO, or it may transmit non-IMS services. These non-IMS services may also be referred to as data services, internet services, etc.

[0017] In this possible implementation, after the terminal device receives a message that does not allow the establishment of an IMS PDN connection, the terminal device determines not to transmit IMS services or to transmit non-IMS services, or in other words, not to transmit IMS services when accessing via GEO.

[0018] The second aspect of this application provides a communication method, which is executed by a terminal, or by a component (e.g., a processor, chip, or chip system) within the terminal, or by a logic module or software capable of implementing all or part of the terminal's functions. In this second aspect and its possible implementations, the method is described as being executed by a terminal device. In this method, the terminal device sends a first message, which requests the establishment of an IMS PDN connection, or the first message is related to third indication information, or the first message is used by a network device to determine the third indication information; the terminal device receives the third indication information, which indicates that the terminal device is permitted to access IMS services via GEO access.

[0019] Optionally, the terminal device sends a first message to the network device. Correspondingly, the terminal device receives a third instruction message sent by the network device.

[0020] Based on the above scheme, the terminal device sends a first message and determines, according to the received third indication information, that it can access the IMS service through GEO access.

[0021] Optionally, in one possible implementation of the second aspect, the first message is also used to indicate at least one of the following: the terminal device supports accessing IMS services via GEO access, the terminal device supports implementing IMS services via IoT transmission, or the terminal device supports at least one DRB.

[0022] In this possible implementation, the information related to GEO, IoT, or DRB indicated by the first message can provide a basis for the network device to send the second message. Alternatively, the information indicated by the first message can be used by the network device to determine whether to allow or authorize the terminal device to establish an IMS PDN connection. In other words, it can be used by the network device to determine whether to establish an IMS PDN connection. Here, the IMS PDN connection can be described as an IMS PDN connection accessed via or based on GEO.

[0023] Alternatively, in one possible implementation of the second aspect, the terminal device may also not transmit IMS services, or may not transmit IMS services when accessing via GEO, or may transmit non-IMS services.

[0024] In this possible implementation, after the terminal device receives a message that does not allow the establishment of an IMS PDN connection, the terminal device determines not to transmit IMS services or to transmit non-IMS services, or in other words, not to transmit IMS services when accessing via GEO.

[0025] A third aspect of this application provides a communication method, which is executed by a network device, or by a component (e.g., a processor, chip, or chip system) within the network device, or by a logic module or software capable of implementing all or part of the network device's functions. In this third aspect and its possible implementations, the method is described as being executed by a network device. In this method, the network device determines whether a terminal device meets preset conditions; and obtains first information from a policy network element or a subscription database, the first information indicating whether the terminal device is allowed to access IMS services via GEO access. Then, based on the preset conditions and the first information, the network device sends a third message or a fourth message to the terminal device, the third message indicating that the terminal device is allowed to establish an IMS PDN connection, and the fourth message indicating that the terminal device is not allowed to establish an IMS PDN connection.

[0026] The preset conditions include one or more of the following: the terminal device accesses via GEO, the terminal device supports accessing IMS services via GEO, the terminal device supports transmitting IMS services via IoT, the terminal device receives a first indication message sent by the network device, or the terminal device supports at least one DRB, wherein the first indication message is used to indicate that an IMS PDN connection is allowed to be established.

[0027] The third and fourth messages can be the same or different.

[0028] Based on the above scheme, the network device determines whether to allow or authorize the terminal device to establish an IMS PDN connection based on whether the terminal device meets preset conditions and / or the first information. The first information is obtained from the policy network element or the subscription database. This enables the network device to make decisions on whether to allow or authorize the terminal device to establish an IMS PDN connection.

[0029] Optionally, in one possible implementation of the third aspect, the network device may also receive a first message, which is used to request the establishment of an IMS PDN connection, or the first message is related to third indication information, or the first message is used by the network device to determine the third indication information; the first message is used to indicate at least one of the following: the terminal device supports accessing IMS services via GEO access, the terminal device supports implementing IMS services via IoT transmission, or the terminal device supports at least one DRB; determining whether the terminal device meets preset conditions includes: determining whether the terminal device meets preset conditions based on the first message.

[0030] In this possible implementation, by indicating GEO, IoT, or DRB-related information through the first message, the network device can determine whether the terminal device meets the preset conditions.

[0031] Optionally, in one possible implementation of the third aspect, sending a third message or a fourth message to the terminal device based on preset conditions and first information includes: if the preset conditions are met, and the first information indicates that the terminal device is allowed to access IMS services via GEO access, then sending a third message.

[0032] In this possible implementation, if preset conditions are met and the first information indicates that the terminal device is allowed or authorized to access IMS services via GEO access, the network device sends a third message to the terminal device. Thus, the terminal device can transmit IMS services, such as registering with an IMS network element or initiating an IMS call.

[0033] Alternatively, in one possible implementation of the third aspect, the third message is also used to indicate whether the terminal device is allowed to access the IMS service via GEO access or non-GEO access.

[0034] Among them, non-GEO access methods include LEO access or access via terrestrial base stations.

[0035] In this possible implementation, the third message can also indicate whether the access to IMS services is via GEO or non-GEO access, so that the terminal device can determine how to access IMS services based on the third message.

[0036] Optionally, in one possible implementation of the third aspect, sending a third message or a fourth message to the terminal device based on preset conditions and first information includes: if the preset conditions are met, and the first information indicates that the terminal device is not allowed to access IMS services via GEO access, then sending a fourth message.

[0037] In this possible implementation, if preset conditions are met and the first message indicates that the terminal device is not allowed to access IMS services via GEO access, the network device sends a fourth message to the terminal device. Therefore, the terminal device can initiate an IMS PDN connection establishment request without using GEO access.

[0038] Alternatively, in one possible implementation of the third aspect, the fourth message is also used to indicate that the terminal device is allowed to access non-IMS services.

[0039] In this possible implementation, the fourth message can also instruct the terminal device to access non-IMS services. That is, in this case, although the fourth message does not allow the terminal device to access IMS services through GEO access, it can allow the terminal device to access non-IMS services.

[0040] The fourth aspect of this application provides a communication device, which is a terminal device, or a component of a terminal device (e.g., a processor, chip, or chip system), or a logic module or software capable of implementing all or part of the functions of the terminal device. Taking the terminal device as an example, the terminal device includes a transceiver unit. Alternatively, the terminal device includes both a transceiver unit and a processing unit.

[0041] The transceiver unit is used to send a first message if preset conditions are met. The first message is used to request the establishment of an Internet Protocol Multimedia Subsystem Public Data Network (IMS PDN) connection.

[0042] The preset conditions include one or more of the following: the terminal device accesses via geostationary orbit (GEO), the terminal device supports accessing IMS services via GEO, the terminal device supports transmitting IMS services via Internet of Things (IoT), the terminal device receives a first indication message from the network device, or the terminal device supports at least one data radio bearer (DRB), and the first indication message is used to indicate permission to establish an IMS PDN connection.

[0043] The transceiver unit is also used to receive a second message, which indicates whether an IMS PDN connection is allowed.

[0044] Optionally, in one possible implementation of the fourth aspect, the first message mentioned above is also used to indicate at least one of the following: the terminal device supports accessing IMS services via GEO access, the terminal device supports implementing IMS services via IoT transmission, or the terminal device supports at least one DRB.

[0045] Alternatively, in one possible implementation of the fourth aspect, the first message described above is used to carry the Access Point Name (APN) of the IMS.

[0046] Optionally, in one possible implementation of the fourth aspect, the second message mentioned above includes second indication information, which is used to indicate that access to IMS services via GEO access is not permitted.

[0047] Optionally, in one possible implementation of the fourth aspect, the aforementioned transceiver unit is further configured not to transmit IMS services, or not to transmit IMS services when accessing via GEO, or to transmit non-IMS services.

[0048] The fifth aspect of this application provides a communication device, which is a terminal device, or a component of a terminal device (e.g., a processor, chip, or chip system), or a logic module or software capable of implementing all or part of the functions of the terminal device. Taking the terminal device as an example, the terminal device includes a transceiver unit. Alternatively, the terminal device includes both a transceiver unit and a processing unit.

[0049] The transceiver unit is used to send a first message, which is used to request the establishment of an IMS PDN connection, or the first message is related to third indication information, or the first message is used by the network device to determine the third indication information;

[0050] The transceiver unit is also used to receive third indication information, which is used to indicate that the terminal device is allowed to access the IMS service via GEO access.

[0051] Optionally, in one possible implementation of the fifth aspect, the first message mentioned above is also used to indicate at least one of the following: the terminal device supports accessing IMS services via GEO access, the terminal device supports implementing IMS services via IoT transmission, or the terminal device supports at least one DRB.

[0052] Optionally, in one possible implementation of the fifth aspect, the aforementioned transceiver unit is further configured not to transmit IMS services, or not to transmit IMS services when accessing via GEO, or to transmit non-IMS services.

[0053] The sixth aspect of this application provides a communication device, which is a network device, or a component of a network device (e.g., a processor, chip, or chip system), or a logic module or software capable of implementing all or part of the functions of a network device. Taking the network device as an example, the network device includes a transceiver unit. Alternatively, the network device includes both a transceiver unit and a processing unit.

[0054] The processing unit is used to determine whether the terminal device meets the preset conditions. The preset conditions include one or more of the following: the terminal device accesses via GEO, the terminal device supports accessing IMS services via GEO, the terminal device supports transmitting IMS services via IoT, the terminal device receives a first indication information sent by the network device, or the terminal device supports at least one DRB. The first indication information is used to indicate that an IMS PDN connection can be established.

[0055] The transceiver unit is used to obtain first information from the policy network element or the subscription database. The first information is used to indicate whether the terminal device is allowed to access the IMS service through GEO access.

[0056] The transceiver unit is also used to send a third message or a fourth message to the terminal device based on preset conditions and first information. The third message is used to indicate that the terminal device is allowed to establish an IMS PDN connection, and the fourth message is used to indicate that the terminal device is not allowed to establish an IMS PDN connection.

[0057] Optionally, in one possible implementation of the sixth aspect, the transceiver unit described above is further configured to receive a first message, the first message being used to request the establishment of an IMS PDN connection; the first message being used to indicate at least one of the following: the terminal device supports accessing IMS services via GEO access, the terminal device supports implementing IMS services via IoT transmission, or the terminal device supports at least one DRB;

[0058] The processing unit is specifically used to determine whether the terminal device meets the preset conditions based on the first message.

[0059] Optionally, in one possible implementation of the sixth aspect, the aforementioned transceiver unit is specifically used to send a third message if, under the condition that the preset conditions are met, the first information indicates that the terminal device is allowed to access the IMS service via GEO access.

[0060] Alternatively, in one possible implementation of the sixth aspect, the aforementioned third message is also used to indicate that the terminal device is allowed to access IMS services via GEO access or non-GEO access.

[0061] Optionally, in one possible implementation of the sixth aspect, the aforementioned transceiver unit is specifically used to send a fourth message if, under the condition that the preset conditions are met, the first information indicates that the terminal device is not allowed to access the IMS service via GEO access.

[0062] Alternatively, in one possible implementation of the sixth aspect, the fourth message described above is also used to indicate that the terminal device is allowed to access non-IMS services.

[0063] A seventh aspect of this application provides a communication device including at least one processor coupled to at least one memory; the at least one memory is used to store a program or instructions; the at least one processor is used to execute the program or instructions to enable the device to implement any possible implementation of the first aspect.

[0064] The eighth aspect of this application provides a communication device including at least one processor coupled to at least one memory; the at least one memory is used to store a program or instructions; the at least one processor is used to execute the program or instructions to enable the device to implement any possible implementation of the second aspect described above.

[0065] The ninth aspect of this application provides a communication device including at least one processor coupled to at least one memory; the at least one memory is used to store a program or instructions; the at least one processor is used to execute the program or instructions to enable the device to implement any possible implementation of the third aspect described above.

[0066] The tenth aspect of this application provides a communication device including at least one logic circuit and at least one input / output interface; the logic circuit is used to perform the method described in any of the possible implementations of the first aspect above.

[0067] The eleventh aspect of this application provides a communication device, including at least one logic circuit and at least one input / output interface; the logic circuit is used to perform a method as described in any of the possible implementations of the second aspect above.

[0068] The twelfth aspect of this application provides a communication device including at least one logic circuit and at least one input / output interface; the logic circuit is used to perform a method as described in any of the possible implementations of the third aspect above.

[0069] The thirteenth aspect of this application provides a communication system comprising a communication device according to any possible implementation of the seventh aspect and any possible implementation of the ninth aspect; or a communication device according to any possible implementation of the eighth aspect and any possible implementation of the ninth aspect; or a communication device according to any possible implementation of the tenth aspect and any possible implementation of the twelfth aspect; or a communication device according to any possible implementation of the eleventh aspect and any possible implementation of the twelfth aspect; or a communication device according to any possible implementation of the ninth aspect; or a communication device according to any possible implementation of the twelfth aspect.

[0070] The fourteenth aspect of this application provides a communication system comprising one or more of the following: a first core network element or a second core network element. The first core network element is used to execute a method of any possible implementation of any of the sixth, ninth, or twelfth aspects described above. The second core network element is used to send first information to the first core network element.

[0071] Optionally, the aforementioned first core network element may include one or more of the following: a mobility management entity (MME) or a session management function (SMF) element, etc. The second core network element may include one or more of the following: a policy control function (PCF), a unified data repository (UDR) element, or a policy and charging rules function (PCRF) element, etc.

[0072] The fifteenth aspect of this application provides a computer-readable storage medium for storing one or more computer-executable instructions, which, when executed by a processor, perform the method as described in any possible implementation of any of the first to third aspects described above.

[0073] The sixteenth aspect of this application provides a computer program product (or computer program) that, when executed by a processor, performs the method described in any possible implementation of any of the first to third aspects described above.

[0074] The seventeenth aspect of this application provides a chip or chip system including at least one processor for supporting a communication device to implement the method described in any possible implementation of any of the first to third aspects described above.

[0075] In one possible design, the chip system may further include at least one memory for storing program instructions and data necessary for the communication device. The chip system may be composed of chips or may include chips and other discrete components. Optionally, the chip system may also include interface circuitry that provides program instructions and / or data to at least one processor.

[0076] The technical effects of any of the design methods in aspects four through seventeen can be found in the technical effects of the different design methods in aspects one through three above, and will not be repeated here. Attached Figure Description

[0077] Figure 1 is a schematic diagram of the communication system provided in this application;

[0078] Figure 2A is another schematic diagram of the communication system provided in this application;

[0079] Figure 2B is another schematic diagram of the communication system provided in this application;

[0080] Figure 3 is a schematic diagram of an IMS network architecture provided in this application;

[0081] Figure 4A is a schematic diagram of the satellite communication process in the transparent transmission mode provided in this application;

[0082] Figure 4B is a schematic diagram of the satellite communication process in the regeneration mode provided in this application;

[0083] Figure 5 is a flowchart illustrating the communication method provided in this application;

[0084] Figure 6 is another flowchart illustrating the communication method provided in this application;

[0085] Figures 7 to 10 are several structural schematic diagrams of the communication device involved in this application. Detailed Implementation

[0086] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings.

[0087] First, some terms used in the embodiments of this application will be explained to facilitate understanding by those skilled in the art.

[0088] 1. In this application, "for indicating" can include both direct and indirect indication. When describing an indication information as indicating A, it can be understood that the indication information carries A, directly indicates A, or indirectly indicates A.

[0089] In this application, the information indicated by the instruction information is called the information to be instructed. In specific implementation, there are many ways to instruct the information to be instructed. For example, it can be implemented through direct instruction, such as through the information to be instructed itself or its index. It can also be implemented indirectly by instructing other information, where there is a relationship between the other information and the information to be instructed. Alternatively, only a part of the information to be instructed can be indicated, while the other parts are known or pre-agreed upon. For example, the instruction of specific information can be achieved by using a pre-agreed (e.g., protocol-defined) arrangement of various pieces of information, thereby reducing instruction overhead to some extent.

[0090] The information to be indicated can be sent as a whole or divided into multiple sub-information messages, and the sending period and / or timing of these sub-information messages can be the same or different. This application does not limit the specific sending method. The sending period and / or timing of these sub-information messages can be predefined, for example, according to a protocol, or configured by the transmitting device by sending configuration information to the receiving device. This configuration information can include, for example, but not limited to, one or a combination of at least two of RRC signaling, medium access control (MAC) layer signaling, and physical layer signaling. MAC layer signaling includes, for example, MAC CE; physical layer signaling includes, for example, downlink control information (DCI).

[0091] 2. In the embodiments of this application, "sending" and "receiving" refer to the direction of signal transmission. In this application, entity A sends information to entity B, either directly or indirectly through other entities. Similarly, entity B receives information from entity A, either directly or indirectly through other entities. Entities A and B can be RAN nodes or terminals, or modules within RAN nodes or terminals. Information sending and receiving can be information interaction between RAN nodes and terminals, such as information interaction between a base station and a terminal; information sending and receiving can also be information interaction between two RAN nodes, such as information interaction between a CU and a DU; information sending and receiving can also be information interaction between different modules within a device, such as information interaction between a terminal chip and other modules of the terminal, or information interaction between a base station chip and other modules in the base station. "Sending" can also be understood as the "output" of the chip interface, such as the baseband chip outputting information to the radio frequency chip, and "receiving" can also be understood as the "input" of the chip interface; for example, "sending" can also be understood as the baseband part inside the device outputting information to the radio frequency part, and "receiving" can also be understood as the radio frequency part inside the device receiving the information output by the baseband part.

[0092] 3. The terms "system" and "network" in the embodiments of this application can be used interchangeably. "At least one" and "one or more" can be used interchangeably, referring to one or more, while "more" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects have an "or" relationship. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, "at least one of A, B, and C" includes A, B, C, AB, AC, BC, or ABC. And, unless otherwise specified, the ordinal numbers such as "first" and "second" mentioned in the embodiments of this application are used to distinguish multiple objects and are not used to limit the order, sequence, priority, or importance of multiple objects.

[0093] 4. Internet Protocol (IP) Multimedia Subsystem (IMS)

[0094] IMS can be understood as a standardized architecture framework that provides IP multimedia services.

[0095] Optionally, IMS typically uses a separate access point name (APN), such as the IMS APN. This is different from the APN used for accessing the Internet (this type of service can be called a data service).

[0096] For example, IMS services specifically include: IMS signaling and IMS voice. IMS signaling has a QoS (quality of service) parameter, Quality of Service Class Identifier (QCI), of 5, corresponding to a non-guaranteed bit rate (GBR) resource type. IMS voice has a QoS parameter, QCI, of 1, corresponding to a GBR resource type.

[0097] Please refer to Figure 1, which illustrates a system architecture provided in this application. This system architecture includes: terminal equipment, radio access network (RAN) equipment, core network (CN), and digital network (DN).

[0098] The Core Network (CN) is responsible for maintaining the subscription data of the mobile network, managing the network elements of the mobile network, and providing functions such as session management, mobility management, policy management, and security authentication for terminal devices. When a terminal device attaches, it provides network access authentication; when a terminal device makes a service request, it allocates network resources to the terminal device; when a terminal device moves, it updates network resources for the terminal device; when a terminal device is idle, it provides a fast recovery mechanism; when a terminal device detaches, it releases network resources for the terminal device; and when a terminal device has service data, it provides data routing functions, such as forwarding uplink data to the data network; or receiving downlink data from the terminal device from the data network and forwarding it to the radio access network (RAN) to send it to the terminal device. Furthermore, the network elements included in the core network may vary depending on the applicable communication system; illustrative descriptions of the network elements included in the core network will follow with reference to Figures 2A and 2B.

[0099] A radio access network (RAN) can be understood as an access network that uses wireless communication technology to provide network access functions. RAN manages radio resources, provides access services to terminal devices, and facilitates the forwarding of control signals and user data between terminal devices and the core network.

[0100] A data network (DN) provides services to terminal devices. Typically, the client is located on the terminal device, and the server is located on the data network. A data network can be a private network, such as a local area network (LAN), an external network not controlled by the operator, such as the Internet, or a proprietary network jointly deployed by operators, such as a network providing IMS services. In short, a data network is used to provide data transmission. Examples include operator networks, the Internet, and third-party service networks.

[0101] In this embodiment of the application, the terminal device may be a wireless terminal device capable of receiving network device scheduling and instruction information. The wireless terminal device may be a device that provides voice and / or data connectivity to the user, or a handheld device with wireless connection function, or other processing device connected to a wireless modem.

[0102] Optionally, the terminal device can be a communication kit with wireless communication capabilities (the kit may include, for example, an antenna, a power supply module, cables, and a Wi-Fi module). The terminal device can also be a communication module with satellite communication capabilities, a satellite phone or a component thereof, or a very small aperture terminal (VSAT). The terminal device can be a mobile terminal device, such as a mobile phone (or "cellular" phone), a computer, or a data card. For example, it can be a portable, pocket-sized, handheld, computer-embedded, or vehicle-mounted mobile device that exchanges voice and / or data with a wireless access network. Examples include personal communication service (PCS) phones, cordless phones, session initiation protocol (SIP) phones, wireless local loop (WLL) stations, personal digital assistants (PDAs), tablets, and computers with wireless transceiver capabilities. Wireless terminal equipment can also be referred to as a system, subscriber unit, subscriber station, mobile station, mobile station (MS), remote station, access point (AP), remote terminal, access terminal, user terminal, user agent, subscriber station (SS), customer premises equipment (CPE), terminal, user equipment (UE), mobile terminal (MT), drone, etc. Terminal equipment can also be wearable devices and next-generation communication systems, such as terminal equipment in future communication systems or terminal equipment in future evolved public land mobile networks (PLMNs). Of course, in this application, terminal equipment can also refer to chips, modems, system-on-a-chip (SoC), or communication platforms that may include radio frequency (RF) components, etc., that are primarily responsible for related communication functions.

[0103] Network devices can be devices within a wireless network. For example, a network device can be a radio access network (RAN) node (or device) that connects terminal devices to the wireless network; it can also be called a base station. Currently, some examples of RAN devices include: next-generation base stations, transmission reception points (TRPs), evolved Node Bs (eNBs), radio network controllers (RNCs), Node Bs (NBs), base station controllers (BSCs), base transceiver stations (BTSs), home base stations (e.g., home evolved Node Bs or home Node Bs (HNBs)), base band units (BBUs), or wireless fidelity (Wi-Fi) access points (APs). Additionally, in a network architecture, network devices can include centralized unit (CU) nodes, distributed unit (DU) nodes, or RAN devices that include both CU and DU nodes.

[0104] In some implementations, the network equipment may also include satellites, aircraft, drones, and ground station equipment connected to satellites, aircraft, and drones.

[0105] Optionally, the network device can send configuration information (e.g., carried in scheduling messages and / or indication messages) to the terminal device, and the terminal device further configures the network according to the configuration information, so that the network configurations of the network device and the terminal device are aligned; or, the network configurations of the network device and the terminal device can be aligned through preset network configurations on the network device and preset network configurations on the terminal device. Specifically, "alignment" means that when there are interactive messages between the network device and the terminal device, their understanding of the carrier frequency for sending and receiving interactive messages, the determination of the interactive message type, the meaning of the field information carried in the interactive message, or other configurations of the interactive message is consistent.

[0106] Furthermore, in other possible cases, the network device can be any other device that provides wireless communication functionality to the terminal device. The embodiments of this application do not limit the specific technology or device form employed by the network device.

[0107] In this application embodiment, the device for implementing the function of the network device can be the network device itself, or it can be a device capable of supporting the network device in implementing that function, such as a chip system, which can be installed in the network device. In the technical solutions provided in this application embodiment, the example of a network device being used to implement the function of the network device is used to describe the technical solutions provided in this application embodiment.

[0108] Optionally, logically, the system architecture shown in Figure 1 can be divided into two parts: the user plane and the control plane. The control plane is responsible for the management of the mobile network, while the user plane is responsible for the transmission of service data. In Figure 1, the NG2 reference point is located between the radio access network control plane and the core network control plane, the NG3 reference point is located between the radio access network user plane and the core network user plane, and the NG6 reference point is located between the core network user plane and the data network.

[0109] It is understandable that the connections in Figure 1 are only examples of some scenarios. In future communication systems, for example, terminal devices may also communicate directly with the core network. Similarly, wireless access network devices may communicate directly with the data network.

[0110] In one possible implementation, the system architecture shown in Figure 1 can specifically be the 4G system architecture shown in Figure 2A. The network elements / devices in this 4G system architecture include: terminal equipment (UE as an example in Figure 2A), mobility management entity (MME), serving GPRS support node (SGSN), home subscriber server (HSS), serving gateway (SGW), public data network gateway (PDN gateway, PGW), policy and charging rules function (PCRF) entity, evolved universal terrestrial radio access network (E-UTRAN), etc.

[0111] E-UTRAN includes multiple evolved nodeBs (eNodeBs). The eNodeBs are interconnected with each other through the X2 interface, and the eNodeBs are interconnected with the evolved packet core (EPC) through the S1 interface. The eNodeBs are interconnected with terminal equipment through LTE-Uu.

[0112] The main functions of the MME are to support NAS messages and their security, manage the track area (TA) list, select P-GW and S-GW, select the MME during handover across MMEs, select the SGSN during handover to 2G / 3G access systems, authenticate terminal devices, roaming control and bearer management, and manage mobility between core network nodes of different access networks under the 3rd Generation Partnership Project (3GPP).

[0113] An S-GW is a gateway terminating at the E-UTRAN interface. Its main functions include: serving as a local anchor point during inter-base station handovers and assisting in base station reordering; serving as a mobility anchor point during handovers between different 3GPP access systems; performing lawful eavesdropping; routing and forwarding data packets; performing packet marking at the uplink and downlink transport layers; and being used for inter-carrier billing, etc.

[0114] A P-GW is a gateway that terminates at the SGi interface for a PDN. If an end device accesses multiple PDNs, it will correspond to one or more P-GWs. The main functions of a P-GW include packet filtering based on the end device, lawful eavesdropping, Internet Protocol (IP) address allocation for interconnection between end devices, packet delivery level marking in the uplink, uplink and downlink service level accounting and service level threshold control, and service-based uplink and downlink rate control.

[0115] HSS is a database used to store subscription information of terminal devices. The home network can contain one or more HSSs. HSS is responsible for storing information related to terminal devices, such as terminal device identifier, number and routing information, security information, location information, profile information, etc.

[0116] The SGSN can be used for signaling interaction when moving between 2G / 3G and E-UTRAN 3GPP access networks, including the selection of P-GW and S-GW, and the selection of MME for terminal equipment switching to E-UTRAN 3GPP access networks.

[0117] PCRF entities terminate at the Rx and Gx interfaces. In non-roaming scenarios, within the home public land mobile network (HPLMN), there is only one PCRF associated with one IP-connectivity access network and IP-CAN session of the terminal device. In roaming scenarios where the service flow is localized, there may be two PCRFs associated with one terminal device's IP-CAN session.

[0118] In another possible implementation, the system architecture shown in Figure 1 can specifically be the 5G system architecture shown in Figure 2B. The network elements / devices in this 5G system architecture include: terminal equipment (UE as an example in Figure 2B), DN, RAN, network slice selection function (NSSF) network element, network exposure function (NEF) network element, network repository function (NRF) network element, policy control function (PCF) network element, unified data management (UDM) network element, application function (AF) network element, authentication server function (AUSF) network element, access and mobility management function (AMF) network element, session management function (SMF) network element, service communication proxy (SCP) network element, and user plane function (UPF) network element.

[0119] Optionally, the system architecture shown in Figure 2B may also include other network elements not shown in the figure, such as network slice-specific authentication and authorization function (NSSAAF) network elements, network slice admission control function (NSACF) network elements, unified data storage (UDR) network elements, etc., which are not limited here.

[0120] The following is an introduction to several key network elements included in the CN:

[0121] 1. AMF network element: responsible for user mobility management, including mobility status management, assigning temporary user identities, authenticating and authorizing users.

[0122] 2. UDM network element: Responsible for managing contract data. When the contract data is modified, it is responsible for notifying the corresponding network element.

[0123] 3. NSSF network element: responsible for selecting network slices.

[0124] 4. SMF network element: Responsible for user plane (UP) network element selection, UP network element reselection, Internet Protocol (IP) address allocation, session establishment, modification and release, and Quality of Service (QoS) control.

[0125] 5. AUSF network element: mainly responsible for network security, used to generate keys, realize two-way authentication for UE, and realize 3GPP and non-3GPP access authentication.

[0126] 6. NEF Network Elements: Open up the capabilities of various network elements, transform internal and external information, and use them for edge computing scenarios.

[0127] 7. PCF network element: mainly used for managing policy rules and user subscription information, etc.

[0128] 8. UDR Network Element: Stores and retrieves subscription data, policy data, and public architecture data, providing relevant data to UDM, PCF, and NEF. The UDR should have different data access authentication mechanisms for different types of data, such as subscription data and policy data, to ensure data access security. The UDR should be able to return a failure response with an appropriate reason value for illegal service operations or data access requests.

[0129] 9. NRF Network Element: Responsible for the registration and discovery functions of network elements, and maintaining information about the network element, such as the instance identifier, type, PLMN, slice-related identifiers, IP address or fully qualified domain name (FQDN), the capabilities of the network element, and supported services.

[0130] 10. AF Network Element: Primarily used to send data routing information affecting applications to the network, and to perform policy control through interaction with the policy framework via network open function network elements.

[0131] 11. UPF Network Element: Interconnects Protocol Data Unit (PDU) sessions with the data network, performs packet routing and forwarding, and detects packets.

[0132] To facilitate understanding, the similarities between 4G and 5G architectures are described below. For example, the 4G MME functions similarly to the 5G AMF+SMF. That is, the MME can be understood as AMF+SMF. Another example is that the 4G SGW is similar to the 5G UPF, and also has some SMF functions. Similarly, the 4G PGW is similar to the 5G UPF, and also has some SMF functions. Furthermore, the 4G PCRF is similar to the 5G PCF. The 4G SCEF is similar to the 5G PCF. Finally, the 4G HSS is similar to the 5G UDM.

[0133] It is understood that the network architecture applicable to the embodiments of this application is not limited to Figure 2A or Figure 2B. Any network architecture capable of realizing the functions of the above-mentioned network elements is applicable to the embodiments of this application. In addition, the network elements included in the core network can be independent devices or integrated into the same device to realize different functions. This application does not limit the specific form of the above-mentioned network elements.

[0134] This application can be applied to long term evolution (LTE) systems, new radio (NR) systems, or new radio vehicle-to-everything (NR V2X) systems; it can also be applied to systems with hybrid LTE and 5G networks; or device-to-device (D2D) communication systems, machine-to-machine (M2M) communication systems, Internet of Things (IoT) systems, or drone communication systems; or communication systems that support multiple wireless technologies, such as those supporting LTE and NR technologies; or non-terrestrial communication systems, such as satellite communication systems and high-altitude communication platforms. Alternatively, this communication system can also be applied to narrowband Internet of Things (NB-IoT), enhanced data rate for GSM evolution (EDGE), wideband code division multiple access (WCDMA), code division multiple access 2000 (CDMA2000), time division-synchronization code division multiple access (TD-SCDMA), and future-oriented communication technologies.

[0135] It should be noted that the above naming is defined solely for the purpose of distinguishing different functions and should not constitute any limitation on this application. This application does not preclude the possibility of using other naming conventions in 5G networks and other future networks. For example, in future communication networks, some or all of the above-mentioned network elements may use the terminology from 5G, or they may use other names. The interface names between the network elements in Figures 1 to 2B are merely examples; the names of the interfaces in specific implementations may be different, and this application does not impose any specific limitations on this. Furthermore, the names of the messages (or signaling) transmitted between the above-mentioned network elements are also merely examples and do not constitute any limitation on the function of the messages themselves.

[0136] It is understood that Figures 2A and 2B above are just two examples of the system architecture in Figure 1. In practical applications, the system architecture shown in Figure 1 can also take other forms, which are not limited here.

[0137] For example, the DN in Figures 1 to 2B above can be an IMS network. IMS is one of the core technologies of network communication, which can meet the needs of terminals for newer and more diversified multimedia services. It is an important way to solve the convergence of mobile and fixed networks and introduce differentiated services such as voice, data, and video triple convergence. The IMS network will be briefly introduced below with reference to Figure 3.

[0138] Figure 3 is a schematic diagram of the IMS network architecture. As shown in Figure 3, the IMS network may include: a telephony application server (TAS), a proxy-call session control function (P-CSCF) entity, a serving-call session control function (S-CSCF) entity, an IMS access gateway (IMS-AGW), a transition gateway (TrGW), an interconnection border control function (IBCF) entity, a breakout gateway control function (BGCF) entity, a media gateway control function (MGCF) entity, etc.

[0139] TAS provides voice and multimedia calling services for users of fixed and mobile converged networks, supports related basic and supplementary services, integrates fixed and mobile converged services on the same platform, and provides a unified service experience for fixed and mobile network users.

[0140] The S-CSCF entity is the central node of the IMS network, responsible for user registration, authentication, sessions, routing, and service triggering.

[0141] The P-CSCF entity is the entry point node for Session Initiation Protocol (SIP) users to access the IMS network, and is mainly responsible for forwarding SIP signaling between SIP users and the home network.

[0142] IMS-AGW is the IMS access gateway, primarily responsible for media plane interoperability between the user and network interfaces.

[0143] TrGW is the IMS interconnection gateway, responsible for media plane interconnection between network interfaces.

[0144] The IBCF entity is primarily used to enable interoperability between the IMS network and other IMS network control planes. For example, if the calling party is on China Mobile's IMS network and the called party is on China Telecom's IMS network, the BGCF entity is responsible for selecting an MGCF entity for the call to connect to the CS network when the calling party is an IMS user and the called party is a circuit-switched (CS) network user.

[0145] The MGCF entity is primarily used to enable interoperability between the IMS network and the control plane of other non-IP networks (such as the public switched telephone network, PSTN).

[0146] It is understandable that other networks besides IMS (such as CS or IMS) can also be referred to as B party when acting as the caller or the called party in real-time audio and video communication.

[0147] To facilitate understanding, the differences between 4G and 5G architectures are described below. For example, in a 5G system, the terminal device first registers with the network and establishes an IMS Protocol Data Unit (PDU) session to carry voice data and signaling. The PDU session establishment process establishes a user plane connection between the terminal device and IMS. Afterward, the terminal device initiates IMS signaling interactions with IMS through the established IMS PDU session, including 1) IMS registration, such as to complete service authorization; and 2) an IMS call process to call the called terminal device. During this process, the establishment of a GBR QoS flow is triggered for voice data transmission. A similar process occurs in a 4G system. The differences from 5G are: 1) In 4G, the user plane connection carrying voice data and signaling is called a PDN connection, and the corresponding PDN connection establishment process corresponds to the PDU session establishment process in 5G; 2) The GBR QoS flow is called a dedicated bearer. In addition, in 4G, a PDN connection can be established during the attachment process of the terminal device.

[0148] Furthermore, the technical solutions of this application embodiment can also be applied to communication systems that integrate terrestrial and satellite communications, which can also be called non-terrestrial network (NTN) communication systems. In other words, the RAN in Figures 1 to 2B can include terrestrial base stations, which can include TN cells (i.e., the signals of the TN cells can be transmitted and received through the terrestrial base station); and the RAN can also include non-terrestrial base stations. Taking a satellite as an example, the non-terrestrial base station can include NTN cells (i.e., the signals of the NTN cells can be transmitted and received through the satellite). The terrestrial communication system can be, for example, a long term evolution (LTE) system, a universal mobile telecommunication system (UMTS), a 5G communication system, or a new radio (NR) system, or a future communication system that is the next step in the development of 5G communication systems, etc., and is not limited here.

[0149] Among these advantages, satellite communication offers wider coverage compared to traditional mobile communication systems. Communication costs are independent of transmission distance, and it can overcome natural geographical barriers such as oceans, deserts, and mountains. To overcome the shortcomings of traditional communication networks, satellite communication can serve as an effective supplement. It is generally believed that non-terrestrial network communication has different channel characteristics compared to terrestrial network communication, such as large transmission delays and Doppler frequency offset.

[0150] Optionally, satellite communication systems can be categorized into three types based on their orbital altitude: geostationary earth orbit (GEO) satellite communication systems, also known as synchronous orbit satellite systems; medium earth orbit (MEO) satellite communication systems; and low earth orbit (LEO) satellite communication systems. For example, the round-trip time delay for GEO satellite communication is 238–270 milliseconds (ms). The round-trip time delay for LEO satellite communication is 8 ms–20 ms. Furthermore, NTN systems may also include highly elliptical orbit (HEO) satellites, high altitude platform station (HAPS) communication systems, and other aerial network equipment; specific details are not limited here.

[0151] GEO satellites, also known as high-orbit satellites, orbit at an altitude of 35,786 kilometers. Their main advantages are relative stationary position and large coverage area. However, GEO satellites also have significant drawbacks: the large distance from Earth necessitates larger antennas; their transmission latency is relatively high, around 0.5 seconds, failing to meet real-time service requirements; and orbital resources are relatively scarce, resulting in high launch costs and an inability to provide coverage to polar regions. MEO satellites, orbiting at altitudes between 2,000 and 35,786 km, can achieve global coverage with a relatively small number of satellites, but their transmission latency is higher than that of LEO satellites, and they are primarily used for positioning and navigation. Furthermore, satellites orbiting at altitudes between 300 and 2,000 km are called low-orbit (LEO) satellites. LEO satellites are lower in altitude than MEO and GEO satellites, resulting in lower data propagation latency, lower power loss, and relatively lower launch costs. Therefore, LEO satellite communication networks have made significant progress and attracted considerable attention in recent years.

[0152] In addition, satellite equipment can be divided into transparent mode and regenerative mode according to its working mode.

[0153] For example, Figure 4A shows an example of a transparent payload mode (or transparent mode) in which the NTN communication system is combined with the IMS network. The system architecture in this example includes: terminal equipment, satellite, gateway station (also called gateway station, ground station, earth station, etc.), base station, core network, and IMS network.

[0154] Specifically, satellites and gateway stations can act as relays for communication between terminal devices and base stations, transparently transmitting signals between satellites and terminal devices. For example, a gateway station can access the core network through a base station, and then access the IMS network. In transparent transmission mode, the satellite only performs transparent forwarding. The network elements / devices in Figure 4A can be referenced in the aforementioned system architecture description, and will not be repeated here.

[0155] For example, Figure 4B illustrates a regenerative mode combining an NTN communication system with an IMS network. The system architecture in this example includes: terminal equipment, satellite ("base station onboarding"), gateway, core network, and IMS network. Specifically, the satellite in regenerative mode needs to possess all or some of the functions of a base station. The network elements / equipment in Figure 4B can be referenced in the aforementioned system architecture description, and will not be repeated here.

[0156] It should be understood that the number of each device / network element in Figures 1 to 4B is only an example. In actual applications, the specific number of devices / network elements included in each of the above systems is not limited here.

[0157] Terminal devices can make calls via IMS. For example, the terminal device first registers with the network in the 5G system, establishing an IMS PDU session to carry call data and signaling. This process mainly involves the interaction between the terminal device and the 5G core network (5GC). Then, the terminal device initiates IMS registration through the established IMS PDU session, establishing an IMS session, and subsequently transmits voice data through the IMS session. However, with the introduction of diverse terminal devices, such as smart terminals, handheld terminals, and IoT terminals, some terminals may be limited by their capabilities and may not need to transmit IMS services.

[0158] To address the aforementioned technical problems, this application offers several approaches:

[0159] The first approach involves the terminal device triggering the establishment of an IMS PDN connection based on preset conditions. On one hand, the preset conditions for the terminal device to request the establishment of an IMS PDN connection are defined. On the other hand, by limiting the preset conditions to be related to GEO, the decision to establish an IMS PDN connection for certain terminal devices in GEO scenarios can be explicitly made. For example, the preset conditions may include one or more of the following: the terminal device accesses via GEO, or the terminal device supports accessing IMS services via GEO. Alternatively, by limiting the preset conditions to be related to specific terminals (e.g., terminals that support IMS service transmission via IoT, terminals that support at least one DRB, or terminals that have received the first indication information), unnecessary IMS PDN connections established by non-specific terminals can be reduced.

[0160] The second approach involves the network device determining whether to allow a terminal device to establish an IMS PDN connection based on whether the terminal device meets preset conditions and / or the first piece of information. This first piece of information is obtained from a policy network element or a subscription database. This allows the network device to make the decision on whether to allow the terminal device to establish an IMS PDN connection.

[0161] It is understood that the above two approaches can be implemented individually or in combination; no specific limitations are made here. The above approaches will be described in conjunction with different accompanying diagrams later. This application uses a 4G architecture as an example for description.

[0162] Please refer to Figure 5, a flowchart illustrating a communication method according to the first approach provided in this application embodiment. This method may include steps 501 to 503. Steps 501 to 503 can be executed by a communication device, or by some components of the communication device (e.g., a processor, chip, or chip system), or by a logic module or software capable of implementing all or part of the functions of the communication device. The following description uses execution by a communication device as an example. The processing performed by a single executing entity in steps 501 to 503 can also be divided into multiple executing entities, which can be logically and / or physically separated. For example, when the communication device is an access network device, the processing performed by the communication device can be divided into execution by at least one network element such as CU, DU, and RU. As another example, when the communication device is a 4G core network device, the processing performed by the communication device can be divided into execution by at least one network element such as MME or PCRF. As yet another example, when the communication device is a 5G core network device, the processing performed by the communication device can be divided into execution by at least one network element such as SMF or PCF. This method can be applied to any of the system architectures shown in Figures 1 to 4B above, and no specific limitations are made here.

[0163] Step 501: The terminal device determines that the preset conditions are met. This step is optional.

[0164] The preset conditions in this application embodiment include one or more of the following: the terminal device accesses via GEO, the terminal device supports accessing IMS services via GEO, the terminal device supports transmitting IMS services via IoT, the terminal device receives first indication information from the network device, or the terminal device supports at least one DRB, etc., whereby the first indication information is used to indicate permission or authorization to establish an IMS PDN connection.

[0165] The following is a description of each of the above items:

[0166] 1. Terminal devices are accessed via GEO.

[0167] This can be interpreted as: the terminal device accesses via GEO. Alternatively, it can be interpreted as: the terminal device accesses via GEO. Or, it can be interpreted as: the terminal device accesses via NB-IoT (GEO). Or, it can be interpreted as: the terminal device's radio access technology (RAT) type is GEO or NB-IoT (GEO), etc.

[0168] 2. Terminal devices support accessing IMS services via GEO access.

[0169] This can be interpreted as: The terminal device supports IMS over GEO. Alternatively, it can be interpreted as: The terminal device supports accessing IMS services via GEO. Or, it can be interpreted as: The terminal device supports accessing IMS services via NB-IoT (GEO). Or, it can be interpreted as: The terminal device supports low-rate encoding / decoding.

[0170] 3. Terminal devices support the transmission of IMS services via IoT.

[0171] This can be interpreted as: the terminal device is an IoT device.

[0172] Alternatively, it can be interpreted as: the terminal device is a smart terminal or a handheld terminal, etc. For example, the terminal device simultaneously supports NB-IoT access and other access methods. Other access methods can also be called broadband access methods, such as enhanced Machine-Type Communication (eMTC) or Broadband (WB)-EUTRAN, etc.

[0173] For example, an IoT terminal connected via GEO can satisfy both 2 and 3.

[0174] 4. Receive the first instruction information from the network device.

[0175] This can be interpreted as: the terminal device receiving an enable instruction from the network device. Alternatively, it can be interpreted as: the terminal device receiving an activation instruction from the network device. The network device can be an MME or SMF, etc.

[0176] 5. The terminal device supports at least one DRB.

[0177] This can be interpreted as: the terminal device supports one, two, or more DRBs. For example, the terminal device supports one DRB. Alternatively, it can be interpreted as: the terminal device supports user plane-based data transmission. Or, it can be interpreted as: the terminal device supports the capability of multiple DRBs, etc.

[0178] It is understood that the above items are just examples. In other embodiments, there may be other situations, such as the type of terminal device, etc., which are not limited here.

[0179] It should be noted that items 1 to 5 above can be substituted for each other or are equivalent in the following description. For ease of description, the following description will only take "the terminal device accessing IMS services through GEO access" as an example.

[0180] Furthermore, this application does not limit the method by which the terminal device determines whether it meets the preset conditions. The terminal device can be determined based on its capability information, its local configuration, information obtained from a database on the terminal side or network side, or by receiving broadcast messages, etc. Specific methods are not limited here. For example, if the terminal device accesses via GEO, it can determine this based on broadcast messages; if the terminal device supports accessing IMS services via GEO, it can determine this based on its capability information or its local configuration.

[0181] The capability information of the terminal device may include at least one of 1 to 5 above.

[0182] Step 502: The terminal device sends the first message.

[0183] The terminal device sends a first message to the network device. Correspondingly, the network device receives the first message sent by the terminal device. This first message is used to request the establishment of an IMS PDN connection.

[0184] The network equipment includes: access network equipment and / or core network equipment. For example, a terminal device sends a first message to the access network equipment. Correspondingly, the access network equipment receives the first message sent by the terminal device. The access network equipment sends a first message or a processed first message (e.g., adding, deleting, or modifying the first message) to the core network equipment. Correspondingly, the core network equipment receives the first message sent by the access network equipment or the processed first message. As another example, a terminal device sends a first message to the core network equipment. Correspondingly, the core network equipment receives the first message sent by the network equipment.

[0185] For example, the terminal device sends a first message to the access network device. After receiving the first message, the access network device sends an S1 message to the core network device. This S1 message can carry the first message and a RAT indication. The RAT indication is used to indicate whether the terminal device accesses via GEO or NB-IoT (GEO). The core network device can select the appropriate SGW and PGW based on the S1 message. Then, the core network device sends the bearer establishment procedure to the SGW, etc. Alternatively, the IMS PDN connection requested in the first message is a PDN connection between the terminal device, access network device, SGW, and PGW, used to carry IMS services.

[0186] Understandably, in the first approach, steps 501 and 502 can be interpreted as the terminal device sending a first message to the network device if the preset conditions are met. Alternatively, it can be interpreted as the terminal device sending a first message to the network device after determining that the preset conditions are met.

[0187] In addition, the first message can also be understood as a request message. For example, the first message can be an attach request message, a PDN connectivity request message, or a tracking area update (TAU) request message, etc. The specific one is not limited here.

[0188] Optionally, the first message may also indicate at least one of the following: the terminal device supports accessing IMS services via GEO access, the terminal device supports IMS services via IoT transmission, or the terminal device supports at least one DRB, etc.

[0189] Furthermore, the first message can also carry an IMS APN.

[0190] It is understood that the first message may not carry the IMS APN. The first message can also be described as a query to determine whether an IMS PDN connection can be established. Alternatively, the first message may be related to third indication information, or it may be used by the network device to determine the third indication information.

[0191] Optionally, the first message can also be used by the network device to determine whether to allow the terminal device to establish an IMS PDN connection.

[0192] It should be noted that there are several possible scenarios after a network device receives the first message. For example, the network device may directly allow the terminal device to establish an IMS PDN connection. Alternatively, the network device may need to consider certain criteria to determine whether to allow the terminal device to establish an IMS PDN connection. These criteria may include one or more of the following: whether the terminal device meets preset conditions, the terminal device's subscription information, or the terminal device's policy information.

[0193] Step 503: The terminal device receives the second message.

[0194] After the terminal device sends a first message to the network device, the network device sends a second message to the terminal device. Correspondingly, the terminal device receives the second message from the network device. The second message is a response to the first message.

[0195] Furthermore, the second message is used to indicate whether an IMS PDN connection is allowed.

[0196] Similarly, for example, a core network device sends a second message to an access network device, and the access network device receives the second message sent by the core network device. Similarly, an access network device sends a second message to a terminal device, and the terminal device receives the second message sent by the access network device. As another example, a core network device sends a second message to a terminal device, and the terminal device receives the second message sent by the core network device.

[0197] In one possible implementation, the second message indicates whether to allow the establishment of an IMS PDN connection. For example, the second message may include a third message and / or a fourth message. The third message indicates that the terminal device is allowed to establish an IMS PDN connection. That is, the fourth message indicates that the terminal device is not allowed to establish an IMS PDN connection.

[0198] It is understandable that the second message can be equivalent to the third message in some scenarios, and correspondingly, the second message can also be equivalent to the fourth message in some scenarios. For example, this step can also be described as the terminal device receiving either the third or fourth message. The third message is used to indicate that the terminal device is allowed to establish an IMS PDN connection. That is, the fourth message is used to indicate that the terminal device is not allowed to establish an IMS PDN connection.

[0199] In another possible implementation, the second message also indicates whether the terminal device is allowed to access the IMS service via GEO access. For example, the second message may include second indication information and / or third indication information. The second indication information indicates that access to the IMS service via GEO access is not allowed. The third indication information indicates that access to the IMS service via GEO access is allowed.

[0200] For example, the second message indicates one or more of the following: IMS PDN connection is not allowed; terminal devices are not allowed to access IMS services via GEO access. Accordingly, after receiving the second message, the terminal device may choose not to transmit IMS services, or to transmit non-IMS services, or not to transmit IMS services via GEO access (e.g., via IoT packets). Non-IMS services can also be referred to as services other than IMS services, such as Internet services or data services.

[0201] For example, the second message indicates one or more of the following: allowing the establishment of an IMS PDN connection, or allowing the terminal device to access IMS services via GEO access. Accordingly, after receiving the second message, the terminal device can transmit IMS services. For example, accessing IMS services via GEO access. Another example is transmitting IMS services via IoT.

[0202] Optionally, after receiving the second message, the terminal device can register as the calling terminal device with the corresponding IMS network element, or send a call to the called terminal device, etc.

[0203] The method provided in this embodiment has several variations. For example, the method in this embodiment includes steps 501 to 503, whereby the terminal device triggers the establishment of an IMS PDN connection based on preset conditions, meaning the terminal device decides independently whether to initiate the establishment of an IMS PDN connection. Another example is the method in this embodiment, which includes steps 502 and 503, where the terminal device sends a first message without determining whether preset conditions are met. The first message can be sent immediately to the terminal device to allow the network device to determine whether to allow the establishment of an IMS PDN connection via GEO, meaning the terminal device decides whether to allow the establishment of an IMS PDN connection via GEO based on the network device's indication information. Establishing an IMS PDN connection can be described as accessing IMS services.

[0204] In this embodiment, on the one hand, preset conditions are defined for terminal devices to request the establishment of IMS PDN connections. On the other hand, by limiting the preset conditions to be related to GEO, the decision to establish an IMS PDN connection for certain terminal devices in GEO scenarios can be explicitly made. For example, the preset conditions may include one or more of the following: the terminal device accesses via GEO, or the terminal device supports accessing IMS services via GEO. Alternatively, by limiting the preset conditions to be related to specific terminals (e.g., terminals that support IMS service transmission via IoT, terminals that support at least one DRB, or terminals that have received the first indication information), unnecessary IMS PDN connections established by non-specific terminals can be reduced. Furthermore, terminal devices can also establish IMS PDN connections by querying network devices.

[0205] Please refer to Figure 6, a flowchart illustrating a communication method under the second approach provided in this application embodiment. This method may include steps 601 to 606. Steps 601 to 606 can be executed by a communication device, or by some components of the communication device (e.g., a processor, chip, or chip system), or by a logic module or software capable of implementing all or part of the functions of the communication device. The following description uses execution by a communication device as an example. The processing performed by a single execution entity in steps 601 to 606 can also be divided into multiple execution entities, which can be logically and / or physically separated. For example, when the communication device is an access network device, the processing performed by the communication device can be divided into execution by at least one network element such as CU, DU, and RU. This method can be applied to any of the system architectures shown in Figures 1 to 4B above; specific limitations are not specified here.

[0206] Step 601: The terminal device determines that the preset conditions are met. This step is optional.

[0207] Step 602: The terminal device sends the first message to the network device.

[0208] Steps 601 and 602 in this embodiment are similar to steps 501 and 502 in the embodiment shown in Figure 5 above, and will not be described again here.

[0209] Step 603: The network device determines whether the terminal device meets the preset conditions. This step is optional.

[0210] The preset conditions in this embodiment can be referred to the description of step 501 in the embodiment shown in Figure 5 above, and will not be repeated here.

[0211] It should be noted that the method by which the network device determines whether a terminal device meets the preset conditions can be the same as or different from the method by which the terminal device determines whether it meets the preset conditions. That is, there is no limitation on the method by which the network device determines whether a terminal device meets the preset conditions. The network device can determine this based on the terminal device's capability information, its local configuration, information obtained from a subscription database and / or policy network elements, or by receiving information from other devices; the specific method is not limited here. The subscription database can be located on the network device side or on the terminal device side, etc., and the specific method is not limited here.

[0212] For example, when the network device is a core network device, the core network device can determine from the access network device whether the terminal device accesses via GEO. For instance, the core network device obtains the capability information of the terminal device.

[0213] Optionally, the network device determines whether the terminal device meets preset conditions based on the first message. The first message indicates at least one of the following: the terminal device supports accessing IMS services via GEO access, the terminal device supports implementing IMS services via IoT transmission, or the terminal device supports at least one DRB.

[0214] Step 604: The policy network element and / or subscription database send the first information to the network device. This step is optional.

[0215] This step can also be described as the network device obtaining first information from the policy network element or subscription database. This first information is used to indicate whether the terminal device is allowed to access IMS services via GEO access. Alternatively, it can be understood as the first information indicating whether the terminal device allows IMS over GEO.

[0216] This first piece of information can be referred to as policy information or subscription information. For example, network devices obtain policy information from the PCRF. Another example is that network devices obtain subscription information from the HSS. It is understandable that, taking the 4G core network as an example, the network device MME obtains policy information from the PCRF either directly or indirectly. For instance, the MME interacts with the PCRF through the SGW and PGW to obtain policy information.

[0217] Optionally, the first information is used to indicate whether the terminal device is allowed to transmit non-IMS services (or Internet services, data services, etc.).

[0218] Examples of the first information can be shown in Table 1:

[0219] Table 1

[0220] Specifically, in Scenario 1, the policy or subscription information allows the terminal device to access IMS over GEO and also allows the terminal device to access data services. In Scenario 2, the policy or subscription information allows the terminal device to access IMS over GEO but does not allow the terminal device to access data services. In Scenario 3, the policy or subscription information does not allow the terminal device to access IMS over GEO but allows the terminal device to access data services. In Scenario 4, the policy or subscription information does not allow the terminal device to access IMS over GEO and also does not allow the terminal device to access data services.

[0221] Step 605: The network device determines the second message based on preset conditions and / or the first information.

[0222] The network device can determine the second message based on preset conditions and / or the first information. The second message is used to indicate whether the terminal device is allowed to establish an IMS PDN connection.

[0223] Optionally, the second message may include a third or a fourth message. The third message indicates that the terminal device is permitted to establish an IMS PDN connection. The fourth message indicates that the terminal device is not permitted to establish an IMS PDN connection.

[0224] Alternatively, this step can be understood as the network device determining a third or fourth message based on preset conditions and / or the first information. The third message indicates that the terminal device is allowed to establish an IMS PDN connection. The fourth message indicates that the terminal device is not allowed to establish an IMS PDN connection.

[0225] Furthermore, the second message indicates whether the terminal device is allowed to access the IMS service via GEO access. Correspondingly, the third message indicates whether the terminal device is allowed to access the IMS service via GEO access. The fourth message indicates whether the terminal device is not allowed to access the IMS service via GEO access.

[0226] Optionally, the fourth message can also be used to indicate that the terminal device is allowed to access non-IMS services. That is, in this case, although the fourth message does not allow the terminal device to access IMS services via GEO access, it can allow the terminal device to access non-IMS services.

[0227] There are several ways in which a network device determines the second message based on preset conditions and / or first information. For example, the network device determines the second message based on preset conditions. Another example is that the network device determines the second message based on the first information. Yet another example is that the network device can determine the second message based on both preset conditions and the first information.

[0228] Alternatively, it can be understood that the network device determines whether to send a third or fourth message to the terminal device based on preset conditions and / or first information.

[0229] For example, network devices determine whether the second message is a third or fourth message based on preset conditions. For instance, if the terminal device meets the preset conditions, it determines the second message is a third message. Conversely, if the terminal device does not meet the preset conditions, it determines the second message is a fourth message.

[0230] For example, the network device determines whether the second message is a third or fourth message based on the first information. For instance, if the first information indicates that the terminal device is allowed to access IMS services via GEO, then the second message is determined to be a third message. Similarly, if the first information indicates that the terminal device is allowed to access IMS over GEO, then the second message is determined to be a third message. Likewise, if the first information indicates that the terminal device is not allowed to access IMS services via GEO, then the second message is determined to be a fourth message. Finally, if the first information indicates that the terminal device is not allowed to access IMS over GEO, then the second message is determined to be a fourth message.

[0231] For example, the network device determines whether the second message is a third or fourth message based on preset conditions and the first information. For instance, if the first information indicates that the terminal device is allowed to access IMS services via GEO access when the preset conditions are met, then the second message is determined to be a third message. Similarly, if the first information indicates that the terminal device is allowed to access IMS over GEO when the preset conditions are met, then the second message is determined to be a third message.

[0232] For example, if, under preset conditions, the first message indicates that the terminal device is not allowed to access IMS services via GEO, then the second message is determined to be the fourth message. For example, if, under preset conditions, the first message indicates that the terminal device is not allowed to access IMS over GEO, then the second message is determined to be the fourth message.

[0233] For example, if the preset conditions are not met, and the first message indicates that the terminal device is not allowed to access IMS services via GEO, then the second message is determined to be the fourth message.

[0234] For example, if the preset conditions are not met, and the first message indicates that the terminal device is allowed to access IMS services via GEO, then the second message is determined to be the fourth message. For example, if the preset conditions are not met, and the first message indicates that the terminal device is allowed to access IMS over GEO, then the second message is determined to be the fourth message.

[0235] Step 606: The network device sends a second message to the terminal device.

[0236] After determining the second message based on preset conditions and / or first information, the network device sends the second message to the terminal device. Correspondingly, the terminal device receives the second message sent by the network device.

[0237] It is understandable that steps 605 and 606 can also be interpreted as: the network device sending a second message to the terminal device based on preset conditions and / or the first information. Or it can be interpreted as: the network device sending a third or fourth message to the terminal device based on preset conditions and / or the first information.

[0238] For example, if the first message indicates that the terminal device is allowed to access IMS services via GEO access when the preset conditions are met, then the third message is sent.

[0239] For example, if the first message indicates that the terminal device is not allowed to access IMS services via GEO access when the preset conditions are met, then a fourth message is sent.

[0240] Optionally, if the second message received by the terminal device indicates that the terminal device is allowed to access IMS services via GEO access, or if the second message indicates that the terminal device is allowed to establish an IMS PDN connection, then the terminal device can access IMS services, such as initiating IMS registration or an IMS call.

[0241] Optionally, if the second message received by the terminal device indicates that the terminal device is not allowed to access IMS services via GEO access, or if the second message indicates that the terminal device is not allowed to establish an IMS PDN connection, then the terminal device will not initiate the IMS PDN connection establishment process or will not initiate the IMS PDN connection establishment process at all. Of course, the terminal device can initiate the establishment of a PDN connection for non-IMS services.

[0242] For example, taking the first message as an attach request and Table 1 as an example, the above process can be shown in Table 2.

[0243] Table 2

[0244] In Scenario 1, the policy or subscription information allows the terminal device to access IMS over GEO and also allows the terminal device to access data services. The network device can send an attach accept message. If the first message carries an IMS PDN, the terminal device can initiate IMS services (such as IMS registration or IMS call). If the first message does not carry an IMS PDN, the terminal device can initiate an IMS PDN connection.

[0245] Scenario 2 corresponds to policy or subscription information that allows terminal devices to access IMS over GEO, but does not allow them to access data services. The network device can send an attach accept message. If the first message carries an IMS PDN, the terminal device can initiate IMS services (e.g., IMS registration or IMS call). If the first message does not carry an IMS PDN, the terminal device can initiate an IMS PDN connection.

[0246] In Scenario 3, the policy or subscription information may allow terminal devices to access IMS over GEO, or allow them to access data services. Network devices can send attach accept messages or attach reject messages. Terminal devices can then initiate a connection to a data APN to access data services.

[0247] Scenario 4's policy or subscription information disallows terminal devices from accessing IMS over GEO and from accessing data services. Network devices may send attach denial messages. Terminal devices will not initiate IMS PDN or data APN connections.

[0248] It's understandable that scenarios 3 and 4 can also be described as the terminal device initiating an IMS PDN connection without GEO access. Alternatively, it can be understood that this simply means access to IMS via GEO is not supported; IMS PDN connections established through other methods are still possible, such as initiating an IMS PDN connection when accessing via a terrestrial base station. In scenario 3, it can also be understood as the terminal device accessing other services via GEO, or described as the terminal device accessing non-IMS services via GEO, or as the terminal device accessing data services via GEO, such as accessing IoT services via GEO.

[0249] The method provided in this embodiment has several variations. For example, if the method includes steps 602, 603, 605, and 506, the corresponding network device sends a second message to the terminal device according to preset conditions. Alternatively, if the method includes steps 602, 604, and 506, the corresponding network device sends a second message to the terminal device according to first information. Another example is that if the method includes steps 602 and 506, the corresponding network device sends a second message to the terminal device according to preset conditions and first information. Yet another example is that if the method includes steps 601 and 506, the corresponding terminal device sends the first message only when preset conditions are met, and the network device sends the second message to the terminal device according to the preset conditions and first information.

[0250] In this embodiment, the network device determines whether to allow the terminal device to establish an IMS PDN connection based on whether the terminal device meets preset conditions and the first information. The first information is obtained from a policy network element or a subscription database. This enables the network device to decide whether to allow the terminal device to establish an IMS PDN connection.

[0251] The communication methods in the embodiments of this application have been described above. The communication devices in the embodiments of this application are described below. Please refer to Figure 7, which shows an embodiment of the communication device 700 in this application. This communication device 700 can implement the functions of the terminal device or network device in the above method embodiments, and therefore can also achieve the beneficial effects of the above method embodiments. In this application embodiment, the communication device 700 can be a communication device, or it can be an integrated circuit or component inside the communication device, such as a chip. The communication device 700 includes a transceiver unit 701. Alternatively, the communication device 700 includes a transceiver unit 701 and a processing unit 702, wherein the transceiver unit 701 is used to perform operations related to the transmission and reception of the terminal device or network device in the above method embodiments, and the processing unit 702 is used to perform other operations of the terminal device or network device in the above method embodiments besides the transmission and reception operations.

[0252] In one possible implementation, the communication device 700 is the terminal device shown in the embodiments of Figures 1 to 6 above, in which case the functions of each unit are as follows:

[0253] The transceiver unit 701 is used to send a first message if preset conditions are met. The first message is used to request the establishment of an Internet Protocol Multimedia Subsystem Public Data Network (IMS PDN) connection.

[0254] The preset conditions include one or more of the following: the terminal device accesses via geostationary orbit (GEO), the terminal device supports accessing IMS services via GEO, the terminal device supports transmitting IMS services via Internet of Things (IoT), the terminal device receives a first indication message from the network device, or the terminal device supports at least one data radio bearer (DRB), and the first indication message is used to indicate permission to establish an IMS PDN connection.

[0255] The transceiver unit 701 is also used to receive a second message, which indicates whether an IMS PDN connection is allowed.

[0256] Optionally, the first message is also used to indicate at least one of the following: the terminal device supports accessing IMS services via GEO access, the terminal device supports IMS services via IoT transmission, or the terminal device supports at least one DRB.

[0257] Optionally, the first message is used to carry the Access Point Name (APN) of the IMS.

[0258] Optionally, the second message includes a second indication message, which indicates that access to IMS services via GEO access is not permitted.

[0259] Optionally, the transceiver unit 701 is also used to not transmit IMS services, or not transmit IMS services when accessing via GEO, or transmit non-IMS services.

[0260] In this embodiment, the operations performed by each unit in the communication device are similar to those described in the terminal devices shown in the embodiments of Figures 1 to 6 above, and will not be repeated here.

[0261] In this embodiment, under preset conditions, the transceiver unit 701 sends a first message, which is used by the terminal device or network device to establish an IMS PDN connection. On one hand, preset conditions for establishing an IMS PDN connection by the terminal device are defined. On the other hand, by limiting the preset conditions to be related to GEO, the decision to establish an IMS PDN connection for certain terminal devices in a GEO scenario can be explicitly made. For example, the preset conditions may include one or more of the following: the terminal device accesses via GEO, or the terminal device supports accessing IMS services via GEO. Alternatively, by limiting the preset conditions to be related to specific terminals (e.g., terminals that support transmitting IMS services via IoT, terminals that support at least one DRB, or terminals that have received the first indication information), unnecessary IMS PDN connections established by non-specific terminals can be reduced.

[0262] In another possible implementation, the communication device 700 is the terminal device in the embodiments shown in Figures 1 to 6 above, in which case the functions of each unit are as follows:

[0263] The transceiver unit 701 is used to send a first message, which is used to request the establishment of an IMS PDN connection, or the first message is related to third indication information, or the first message is used by the network device to determine the third indication information;

[0264] The transceiver unit 701 is also used to receive third indication information, which is used to indicate that the terminal device is allowed to access the IMS service via GEO access.

[0265] Optionally, the first message is also used to indicate at least one of the following: the terminal device supports accessing IMS services via GEO access, the terminal device supports IMS services via IoT transmission, or the terminal device supports at least one DRB.

[0266] Optionally, the transceiver unit 701 is also used to not transmit IMS services, or not transmit IMS services when accessing via GEO, or transmit non-IMS services.

[0267] In this embodiment, the operations performed by each unit in the communication device are similar to those described in the terminal devices shown in the embodiments of Figures 1 to 6 above, and will not be repeated here.

[0268] In this embodiment, the transceiver unit 701 sends a first message and determines, based on the received third indication information, that the IMS service can be accessed via GEO access.

[0269] In another possible implementation, the communication device 700 is a network device in the embodiments shown in Figures 1 to 6 above, in which case the functions of each unit are as follows:

[0270] Processing unit 702 is used to determine whether the terminal device meets preset conditions. The preset conditions include one or more of the following: the terminal device accesses via GEO, the terminal device supports accessing IMS services via GEO, the terminal device supports transmitting IMS services via IoT, the terminal device receives a first indication information sent by the network device, or the terminal device supports at least one DRB. The first indication information is used to indicate that an IMS PDN connection is allowed to be established.

[0271] The transceiver unit 701 is used to obtain first information from the policy network element or the subscription database. The first information is used to indicate whether the terminal device is allowed to access the IMS service through GEO access.

[0272] The transceiver unit 701 is also used to send a third message or a fourth message to the terminal device based on preset conditions and first information. The third message is used to indicate that the terminal device is allowed to establish an IMS PDN connection, and the fourth message is used to indicate that the terminal device is not allowed to establish an IMS PDN connection.

[0273] Optionally, the transceiver unit 701 is further configured to receive a first message, which is used to request the establishment of an IMS PDN connection; the first message is used to indicate at least one of the following: the terminal device supports accessing IMS services via GEO access, the terminal device supports implementing IMS services via IoT transmission, or the terminal device supports at least one DRB;

[0274] The processing unit 702 is specifically used to determine whether the terminal device meets the preset conditions based on the first message.

[0275] Optionally, the transceiver unit 701 is specifically used to send a third message if the first information indicates that the terminal device is allowed to access the IMS service via GEO access when the preset conditions are met.

[0276] Optionally, the third message may also be used to indicate whether the terminal device is allowed to access IMS services via GEO access or non-GEO access.

[0277] Optionally, the transceiver unit 701 is specifically used to send a fourth message if the first information indicates that the terminal device is not allowed to access the IMS service via GEO access when the preset conditions are met.

[0278] Optionally, the fourth message can also be used to indicate that the terminal device is allowed to access non-IMS services.

[0279] In this embodiment, the operations performed by each unit in the communication device are similar to those described in the network devices shown in the embodiments of Figures 1 to 6 above, and will not be repeated here.

[0280] In this embodiment, the processing unit 702 determines whether to allow the terminal device to establish an IMS PDN connection based on whether the terminal device meets preset conditions and / or first information. The first information is obtained from a policy network element or a subscription database. This enables the network device side to decide whether to allow the terminal device to establish an IMS PDN connection.

[0281] Please refer to Figure 8, which is another schematic structural diagram of the communication device 800 provided in this application. The communication device 800 includes a logic circuit 801 and an input / output interface 802. The communication device 800 can be a chip or an integrated circuit.

[0282] Optionally, the input / output interface 802 in FIG8 can be equivalent to the transceiver unit 701 shown in FIG7, and the input / output interface 802 may include an input interface and an output interface. Alternatively, the communication interface may also be a transceiver circuit, which may include an input interface circuit and an output interface circuit. The logic circuit 801 in FIG8 can be equivalent to the processing unit 702 shown in FIG7.

[0283] The logic circuit 801 and the input / output interface 802 can also perform other steps executed by the network device or terminal device in any embodiment and achieve corresponding beneficial effects, which will not be elaborated here.

[0284] For example, when the communication device 800 is a terminal device, the input / output interface 802 can be used for one or more of the following: sending a first message, receiving a second message, receiving first information, etc. The logic circuit 801 can be used to determine whether preset conditions are met, etc.

[0285] For example, if the communication device 800 is a network device, the input / output interface 802 can be used for one or more of the following: receiving a first message, sending a second message, etc.

[0286] Optionally, the logic circuit 801 can be a processing device, the functions of which can be partially or entirely implemented in software.

[0287] Optionally, the processing apparatus may include a memory and a processor, wherein the memory is used to store a computer program, and the processor reads and executes the computer program stored in the memory to perform the corresponding processing and / or steps in any of the method embodiments.

[0288] Optionally, the processing device may consist of only a processor. A memory for storing computer programs is located outside the processing device, and the processor is connected to the memory via circuitry / wires to read and execute the computer programs stored in the memory. The memory and processor may be integrated together or physically independent of each other.

[0289] Optionally, the processing device may be one or more chips, or one or more integrated circuits. For example, the processing device may be one or more field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), system-on-chips (SoCs), central processing units (CPUs), network processors (NPs), digital signal processors (DSPs), microcontroller units (MCUs), programmable logic devices (PLDs), or other integrated chips, or any group of the above chips or processors.

[0290] Please refer to Figure 9, which shows the communication device 900 involved in the above embodiments provided in the embodiments of this application. Specifically, the communication device 900 can be a communication device that serves as a network device or a terminal device in the above embodiments, or it can be a chip or functional module in a network device or a terminal device.

[0291] The present invention provides a possible logical structure diagram of the communication device 900, which may include, but is not limited to, at least one processor 901 and a communication port 902.

[0292] Optionally, the communication port 902 in FIG9 can be equivalent to the transceiver unit 701 shown in FIG7, and the communication port 902 may include an input interface and an output interface. Alternatively, the communication port 902 may also be a transceiver circuit, which may include an input interface circuit and an output interface circuit.

[0293] Further optionally, the device may also include at least one of a memory 903 and a bus. In embodiments of this application, the at least one processor 901 is used to control the operation of the communication device 900. The memory 903 is used to store device program code and / or data. Optionally, the processor 901 may be equivalent to the processing unit 702 shown in FIG. 7.

[0294] For example, when the communication device 900 is a terminal device, the communication port 902 can be used for one or more of the following: sending a first message, receiving a second message, receiving first information, etc. At least one processor 901 can be used to determine whether preset conditions are met, etc.

[0295] For example, if the communication device 900 is a network device, the communication port 902 can be used for one or more of the following: receiving a first message, sending a second message, etc.

[0296] Furthermore, the processor 901 can be a central processing unit, a general-purpose processor, a digital signal processor, an application-specific integrated circuit, a field-programmable gate array, or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. It can implement or execute the various exemplary logic blocks, modules, and circuits described in conjunction with the disclosure of this application. The processor can also be a combination that implements computing functions, such as a combination of one or more microprocessors, a combination of a digital signal processor and a microprocessor, etc. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0297] It is understood that this application does not limit the number of the various components shown in Figure 9. For example, the number of processors 901, the number of communication ports 902, and the number of memory 903 can each be one or more, and no specific limitation is made here.

[0298] It should be noted that the communication device 900 shown in Figure 9 can be used to implement the steps implemented by the network device or terminal device in the aforementioned method embodiments, and achieve the corresponding technical effects. The specific implementation of the communication device shown in Figure 9 can be referred to the description in the aforementioned method embodiments, and will not be repeated here.

[0299] Please refer to Figure 10, which is a schematic diagram of the structure of the communication device 1000 involved in the above embodiments provided in the embodiments of this application. Specifically, the communication device 1000 can be a communication device as a network device in the above embodiments, and the structure of the communication device can be referred to the structure shown in Figure 10.

[0300] The communication device 1000 includes at least one processor 1011 and at least one network interface 1014. Optionally, the communication device further includes at least one memory 1012, at least one transceiver 1013, and one or more antennas 1015. The processor 1011, memory 1012, transceiver 1013, and network interface 1014 are connected, for example, via a bus. In this embodiment, the connection may include various interfaces, transmission lines, or buses, etc., and this embodiment is not limited thereto. The antenna 1015 is connected to the transceiver 1013. The network interface 1014 enables the communication device to communicate with other communication devices through a communication link. For example, network interface 1014 may include a network interface between the communication device and core network equipment, such as an S1 interface. The network interface may also include a network interface between the communication device and other communication devices (e.g., other network devices or core network equipment), such as an X2 or Xn interface.

[0301] Optionally, the network interface 1014 shown in FIG10 can be equivalent to the transceiver unit 701 shown in FIG7, and the network interface 1014 may include an input interface and an output interface. Alternatively, the network interface 1014 may also be a transceiver circuit, which may include an input interface circuit and an output interface circuit.

[0302] The processor 1011 is primarily used to process communication protocols and communication data, control the entire communication device, execute software programs, and process data from these programs, for example, to support the actions described in the embodiments of the communication device. The communication device may include a baseband processor and a central processing unit (CPU). The baseband processor is primarily used to process communication protocols and communication data, while the CPU is primarily used to control the entire communication device, execute software programs, and process data from these programs. The processor 1011 in Figure 10 can integrate the functions of both a baseband processor and a CPU. Those skilled in the art will understand that the baseband processor and CPU can also be independent processors interconnected via technologies such as buses. Those skilled in the art will understand that the communication device may include multiple baseband processors to adapt to different network standards, and multiple CPUs to enhance its processing capabilities. The various components of the communication device can be connected via various buses. The baseband processor can also be described as a baseband processing circuit or a baseband processing chip. The CPU can also be described as a central processing circuit or a central processing chip. The function of processing communication protocols and communication data can be built into the processor or stored in memory as a software program, which is then executed by the processor to implement the baseband processing function.

[0303] The memory is primarily used to store software programs and data. The memory 1012 can exist independently or be connected to the processor 1011. Optionally, the memory 1012 can be integrated with the processor 1011, for example, integrated within a single chip. The memory 1012 can store program code that executes the technical solutions of the embodiments of this application, and its execution is controlled by the processor 1011. The various types of computer program code being executed can also be considered as drivers for the processor 1011.

[0304] Figure 10 shows only one memory and one processor. In actual communication devices, there can be multiple processors and multiple memories. Memory can also be called storage medium or storage device, etc. Memory can be a storage element on the same chip as the processor, i.e., an on-chip storage element, or it can be a separate storage element; the embodiments of this application do not limit this.

[0305] Transceiver 1013 can be used to support the reception or transmission of radio frequency (RF) signals between a communication device and a terminal. Transceiver 1013 can be connected to antenna 1015. Transceiver 1013 includes a transmitter Tx and a receiver Rx. Specifically, one or more antennas 1015 can receive RF signals. The receiver Rx of transceiver 1013 is used to receive the RF signals from the antennas, convert the RF signals into digital baseband signals or digital intermediate frequency (IF) signals, and provide the digital baseband signals or IF signals to processor 1011 so that processor 1011 can perform further processing on the digital baseband signals or IF signals, such as demodulation and decoding. In addition, the transmitter Tx in transceiver 1013 is also used to receive modulated digital baseband signals or IF signals from processor 1011, convert the modulated digital baseband signals or IF signals into RF signals, and transmit the RF signals through one or more antennas 1015. Specifically, the receiver Rx can selectively perform one or more stages of downmixing and analog-to-digital conversion on the radio frequency signal to obtain a digital baseband signal or a digital intermediate frequency (IF) signal. The order of these downmixing and IF conversion processes is adjustable. The transmitter Tx can selectively perform one or more stages of upmixing and digital-to-analog conversion on the modulated digital baseband signal or digital IF signal to obtain a radio frequency signal. The order of these upmixing and IF conversion processes is also adjustable. The digital baseband signal and the digital IF signal can be collectively referred to as digital signals.

[0306] The transceiver 1013 can also be called a transceiver unit, transceiver, transceiver device, etc. Optionally, the device in the transceiver unit that performs the receiving function can be regarded as the receiving unit, and the device in the transceiver unit that performs the transmitting function can be regarded as the transmitting unit. That is, the transceiver unit includes a receiving unit and a transmitting unit. The receiving unit can also be called a receiver, input port, receiving circuit, etc., and the transmitting unit can be called a transmitter, transmitter, or transmitting circuit, etc.

[0307] For example, transceiver 1013 can be used for one or more of the following: transmitting first indication information, transmitting reference signals corresponding to the first resource set, receiving M channel state information, etc.

[0308] It should be noted that the communication device 1000 shown in Figure 10 can be used to implement the steps implemented by the network device in the aforementioned method embodiments and to achieve the corresponding technical effects of the network device. The specific implementation of the communication device 1000 shown in Figure 10 can be referred to the description in the aforementioned method embodiments, and will not be repeated here.

[0309] When the aforementioned communication device is a chip applied to a terminal, the terminal chip implements the functions of the terminal in the above method embodiments. The terminal chip receives information from other modules (such as an RF module or antenna) in the terminal, information sent to the terminal by the base station; or, the terminal chip sends information to other modules (such as an RF module or antenna) in the terminal, information sent to the base station by the terminal. For example, when the first device is a terminal, the terminal sending information can be understood as the process of the terminal's chip outputting information.

[0310] When the aforementioned communication device is a module applied to a base station, the base station module implements the functions of the base station in the above method embodiments. The base station module receives information from other modules (such as radio frequency modules or antennas) in the base station, information sent by the terminal to the base station; or, the base station module sends information to other modules (such as radio frequency modules or antennas) in the base station, information sent by the base station to the terminal. Here, the base station module can be the baseband chip of the base station, or a DU (Digital Unit) or other modules. The DU can be a DU under an Open Radio Access Network (O-RAN) architecture. For example, when the first device is a base station, the base station sending information can be understood as the process of the base station's chip outputting information.

[0311] The method steps in the embodiments of this application can be implemented in hardware or in software instructions executable by a processor. The software instructions can consist of corresponding software modules, which can be stored in random access memory, flash memory, read-only memory, programmable read-only memory, erasable programmable read-only memory, electrically erasable programmable read-only memory, registers, hard disks, portable hard disks, CD-ROMs, or any other form of storage medium known in the art. An exemplary storage medium is coupled to a processor, enabling the processor to read information from and write information to the storage medium. The storage medium can also be a component of the processor. The processor and storage medium can reside in an ASIC. Alternatively, the ASIC can reside in a base station or terminal. The processor and storage medium can also exist as discrete components in a base station or terminal.

[0312] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented, in whole or in part, as a computer program product. A computer program product includes one or more computer programs or instructions. When a computer program or instruction is loaded and executed on a computer, all or part of the processes or functions of the embodiments of this application are performed. The computer can be a general-purpose computer, a special-purpose computer, a computer network, a network device, a user equipment, or other programmable device. The computer program or instructions can be stored in a computer-readable storage medium or transferred from one computer-readable storage medium to another. For example, a computer program or instructions can be transferred from one website, computer, server, or data center to another website, computer, server, or data center via wired or wireless means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium, such as a floppy disk, hard disk, or magnetic tape; it can also be an optical medium, such as a digital video optical disc; or it can be a semiconductor medium, such as a solid-state drive. The computer-readable storage medium may be a volatile or non-volatile storage medium, or may include both types of storage media.

[0313] In the various embodiments of this application, unless otherwise specified or in case of logical conflict, the terminology and / or descriptions of different embodiments are consistent and can be referenced by each other. The technical features of different embodiments can be combined to form new embodiments according to their inherent logical relationship.

Claims

1. A communication method, characterized in that, The method is applied in a terminal device or a chip of the terminal device, and the method includes: If the preset conditions are met, a first message is sent, which is used to request the establishment of an Internet Protocol Multimedia Subsystem Public Data Network (IMS PDN) connection. The preset conditions include one or more of the following: the terminal device accesses via geostationary orbit (GEO), the terminal device supports accessing IMS services via GEO access, the terminal device supports transmitting the IMS services via Internet of Things (IoT), or receives a first indication message from a network device, or the terminal device supports at least one data radio bearer (DRB), wherein the first indication message is used to indicate permission to establish the IMS PDN connection. A second message is received, which indicates whether the establishment of the IMS PDN connection is permitted.

2. The method according to claim 1, characterized in that, The first message is also used to indicate at least one of the following: the terminal device supports accessing IMS services via the GEO access method, the terminal device supports implementing IMS services via IoT transmission, or the terminal device supports at least one DRB.

3. The method according to claim 1 or 2, characterized in that, The first message is used to carry the Access Point Name (APN) of the IMS.

4. The method according to any one of claims 1 to 3, characterized in that, The second message includes a second indication, which indicates that access to IMS services is not permitted via the GEO access method.

5. The method according to claim 4, characterized in that, The method further includes: The IMS service is not transmitted, or a non-IMS service is transmitted.

6. A communication method, characterized in that, The method is applied in a terminal device or a chip of the terminal device, and the method includes: Send a first message, which is used to request the establishment of an IMS PDN connection; Receive a third instruction message, which is used to indicate that the terminal device is allowed to access IMS services via GEO access.

7. The method according to claim 6, characterized in that, The first message is also used to indicate at least one of the following: the terminal device supports accessing IMS services through the GEO access method, the terminal device supports implementing IMS services through Internet of Things (IoT) transmission, or the terminal device supports at least one DRB.

8. The method according to claim 6 or 7, characterized in that, The method further includes: The IMS service is not transmitted, or a non-IMS service is transmitted.

9. A communication method, characterized in that, The method is applied in a network device or a chip of the network device, and the method includes: Determine whether the terminal device meets the preset conditions, which include one or more of the following: the terminal device accesses via GEO, the terminal device supports accessing IMS services via GEO, the terminal device supports transmitting the IMS services via IoT, or the terminal device receives a first indication information sent by the network device, or the terminal device supports at least one DRB, wherein the first indication information is used to indicate that an IMS PDN connection is allowed to be established. First information is obtained from the policy network element or the subscription database, and the first information is used to indicate whether the terminal device is allowed to access IMS services through the GEO access method; Based on the preset conditions and the first information, a third message or a fourth message is sent to the terminal device. The third message is used to indicate that the terminal device is allowed to establish the IMS PDN connection, and the fourth message is used to indicate that the terminal device is not allowed to establish the IMS PDN connection.

10. The method according to claim 9, characterized in that, The method further includes: Receive a first message, the first message being used to request the establishment of the IMS PDN connection; the first message being used to indicate at least one of the following: the terminal device supports accessing IMS services via the GEO access method, the terminal device supports implementing IMS services via IoT transmission, or the terminal device supports at least one DRB; The process of determining whether the terminal device meets the preset conditions includes: Based on the first message, determine whether the terminal device meets the preset conditions.

11. The method according to claim 9 or 10, characterized in that, Sending a third or fourth message to the terminal device based on the preset conditions and the first information includes: If the first information indicates that the terminal device is allowed to access IMS services via GEO access when the preset conditions are met, then the third message is sent.

12. The method according to any one of claims 9 to 11, characterized in that, The third message is also used to indicate whether the terminal device is allowed to access IMS services via the GEO access method or a non-GEO access method.

13. The method according to claim 9 or 10, characterized in that, Sending a third or fourth message to the terminal device based on the preset conditions and the first information includes: If the first message indicates that the terminal device is not allowed to access IMS services via GEO access when the preset conditions are met, then the fourth message is sent.

14. The method according to claim 13, characterized in that, The fourth message is also used to indicate that the terminal device is allowed to access non-IMS services.

15. A communication device, characterized in that, Includes a module for performing the method as described in any one of claims 1 to 14.

16. A communication device, characterized in that, It includes at least one processor for executing a computer program or instructions in memory to implement the method as described in any one of claims 1 to 14.

17. A chip or chip system, characterized in that, The chip or chip system is used to perform the method as described in any one of claims 1 to 14.

18. A communication system, characterized in that, It includes a communication device for performing the method of any one of claims 1 to 5 and a communication device for performing the method of any one of claims 6 to 8, or a communication device for performing the method of any one of claims 9 to 14.

19. A readable storage medium, characterized in that, The storage medium stores a computer program or instructions, which, when executed by a communication device, implement the method as described in any one of claims 1 to 14.

20. A computer program product, characterized in that, Includes a computer program or instructions that, when run on a computer, cause the computer to perform the method as described in any one of claims 1 to 14.

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