Communication method and related apparatus

Abstract

Embodiments of the present application provide a communication method. The method can be applied to an Internet Protocol Multimedia Subsystem (IMS) registration scenario or a call establishment scenario. In the method, a first IMS network element controls, by means of a second duration, a call-related operation of a first terminal device. In addition, taking into consideration a paging duration, an alert mechanism, a network access mode, a satellite alignment duration, etc. while determining the second duration can mitigate the problem that a call is erroneously terminated due to a fixed value of a timer being less than the paging duration, and can also reduce meaningless waiting by a calling terminal due to the fixed value of the timer being much greater than the paging duration.

Description

Communication method and related apparatus

[0001] The present application claims priority to the Chinese patent application No. 202411296632.7, filed on September 14, 2024, and entitled "A communication method and related apparatus", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to the field of communication technology, and in particular, to a communication method and related apparatus. BACKGROUND

[0003] In satellite communication, the terminal device is far away from the satellite, and the link budget is low. Especially when the user puts the terminal device in the pocket or bag, the antenna of the terminal device cannot be aligned with the satellite, which will cause the terminal device to be unable to normally receive and transmit information. For example, when the user needs to answer the phone (i.e., the called scenario), the terminal device cannot receive the paging message sent by the network, resulting in call failure.

[0004] To solve the above call failure problem, an enhanced paging mechanism or notification mechanism is considered to enable the terminal device to receive the corresponding message when the signal is poor or the link budget is poor. After the terminal device receives the corresponding information, the terminal device can first perform the star operation (e.g., adjust the terminal posture) / move to a better signal position, thereby ensuring the completion of the subsequent communication process.

[0005] Therefore, after introducing the enhanced paging mechanism or notification mechanism, how to further improve the user's communication experience is a hot issue currently discussed. SUMMARY

[0006] The present application provides a communication method and related apparatus. In the case that a first terminal accesses a network through a satellite, a first internet protocol Multimedia Subsystem (IMS) network element controls the operation related to the call of the first terminal device through a second time duration, and considers the enhanced paging mechanism / notification mechanism when determining the second time duration. For example, when determining the second time duration, the first time duration required when calling the terminal device through the enhanced paging mechanism / notification mechanism or the parameter information related to the enhanced paging mechanism / notification mechanism needs to be considered, which can reduce the problems such as call being terminated incorrectly or invalid waiting of the calling terminal due to the mismatch between the second time duration and the enhanced paging mechanism / notification mechanism.

[0007] The first aspect of the present application provides a communication method, which is executed by a first IMS network element, or executed by a part of components (such as a processor, a chip, a chip system, a proxy-call session control function (P-CSCF) entity, or a serving-call session control function (S-CSCF) entity, etc.) in the first IMS network element, or the method can also be implemented by a logic module or software which can realize all or part of the functions of the first IMS network element. The method can be applied to an IMS registration scenario or a call establishment scenario. In the first aspect and possible implementation manners thereof, the method is described by taking an example of being executed by the first IMS network element (which can also be referred to as a called IMS). In the method, the first IMS network element receives first information sent by a first core network element, and determines a second time length based on the first information. The first information is used to indicate a first time length or parameter information for paging a first terminal device. The parameter information can be understood as parameter information which affects the time length for paging / calling the first terminal device. The parameter information includes at least one of the following: whether the first terminal device activates a first mechanism / notification, whether the first terminal device has a first capability, a policy of the first mechanism / notification, an access network mode of the first terminal device, a star-facing time length of the first terminal device, and the like. The second time length is used to control an operation related to a call of the first terminal device.

[0008] The first mechanism / notification can be understood as a mechanism / notification related to a call or paging of the first terminal device, and specific names can be, for example, an Alert mechanism, an enhanced call mechanism, an enhanced call notification, an enhanced paging mechanism, an enhanced paging notification, a resilient notification, a resilient notification, and the like. The present application does not limit the specific names. For the convenience of description, only the Alert mechanism is used to represent the first mechanism / notification for example in the subsequent description.

[0009] Similarly, the first capability can be understood as a capability related to receiving a call or paging of the first terminal device, and specific names can be, for example, an Alert capability, an enhanced call capability, an enhanced paging capability, a resilient capability, and the like. The present application does not limit the specific names. For the convenience of description, only the Alert capability is used to represent the first capability for example in the subsequent description.

[0010] In addition, the core network or the core network device in the embodiments of the present application includes at least one network element, such as a first core network network element, a second core network network element, a third core network network element, and a fourth core network network element. The first core network network element may, for example, be a unified data management (UDM) network element, a home subscriber server (HSS) network element, a policy control function (PCF) network element, a policy and charging rules function (PCRF) network element, and the like. The second core network network element may, for example, be an access and mobility management function (AMF) network element or a mobility management entity (MME), and the like. The third core network network element may, for example, be a session management function (SMF) network element, and the like. The fourth core network network element may, for example, be a user plane function (UPF) network element, and the like.

[0011] Based on the above scheme, the first IMS network element receives the first information sent by the first core network network element. Since the first information is used to indicate the first time length or parameter information for paging the first terminal device. And the parameter information is related to at least one of whether the first terminal device activates the alerting mechanism, the paging strategy of the alerting mechanism, the access network mode of the first terminal device, the star-up time length of the first terminal device, and the like. Further, the second time length is determined based on the first information, and the second time length is used to control the operation related to the call of the first terminal device. Compared with the scheme in which the IMS determines the time length of the timer based on its own mechanism, the above-mentioned manner considers the time length of paging, the alerting mechanism, the access network mode, and the star-up time length and other parameter information that may affect the time length of paging / calling the first terminal device when determining the second time length, which can reduce the problem of call being terminated incorrectly due to the second time length being too small. It can also reduce the invalid waiting of the call terminal due to the second time length being too large. Call being terminated incorrectly can be understood as that the IMS network element does not receive the response of the called terminal within the timeout, and the core network is still paging the called terminal through the enhanced paging mechanism / notification mechanism. The invalid waiting of the calling terminal can be understood as that the IMS network element is still waiting for the response of the called terminal, but in fact the core network has failed to page the called terminal.

[0012] Optionally, in a possible implementation manner of the first aspect, the operation related to the call of the first terminal device includes terminating the call of the first terminal device, or re-sending a call request for calling the first terminal device.

[0013] In the possible implementation, the call of the first terminal device can be terminated or the call request for calling the first terminal device can be re-sent according to the second time length. Thus, the operation related to the call of the first terminal device can be flexibly and accurately controlled according to the second time length.

[0014] Optionally, in a possible implementation of the first aspect, the first IMS network element can further send a call request for calling the first terminal device; and set / start a timer based on the second time length, and if the timer expires, the call of the first terminal device is terminated or the call request is re-sent.

[0015] In the possible implementation, the first IMS network element can set / start a timer based on the second time length when or after sending the call request for calling the first terminal device, and if the timer expires, the call of the first terminal device is terminated or the call request is re-sent. Compared with the scheme in which the IMS determines the time length of the timer based on its own mechanism, the above-mentioned manner considers the paging time length, the alerting mechanism, the access network mode, the time length of the first terminal device in the star state, and other parameter information that can affect the time length of paging / calling the first terminal device, so that the call can be prevented from being terminated by mistake due to the too small second time length, and the invalid waiting of the called terminal can be reduced due to the too large second time length.

[0016] Optionally, in a possible implementation of the first aspect, the first IMS network element can determine the second time length based on the first time length or the parameter information.

[0017] In the possible implementation, the first IMS network element determines the second time length based on the first time length or the parameter information, that is, the second time length for controlling the operation related to the call of the first terminal device considers the first time length of paging the first terminal device, or considers the time length of paging the first terminal device in the satellite access network mode, or considers the time length of the first terminal device in the star state due to the star operation, or considers that the time length is different due to different paging strategies, or considers the time length caused by the paging / calling or the number of times of the alerting mechanism, and the like. That is, by considering the parameter information that can affect the time length of paging / calling the first terminal device, sufficient time can be provided for the first terminal device to enter the connected state and receive the call before the paging, and the false termination of the call or the invalid waiting of the calling terminal can be reduced, so that the call effect can be improved.

[0018] Optionally, in a possible implementation of the first aspect, the first IMS network element can further send the second time length to a second Internet Protocol Multimedia Subsystem (IMS) network element.

[0019] In the possible implementation, the first IMS network element can also send the second time length to the second IMS network element, so that the second IMS network element prompts the first terminal device to wait for a called response according to the second time length, thereby reducing the call end caused by the hang-up of the first terminal device.

[0020] The second aspect of the present application provides a communication method, which is executed by a first core network element, or executed by part of components (such as a processor, a chip, a chip system, a UDM network element, a HSS network element, a PCF network element, a PCRF network element, etc.) in the first core network element, or the method can also be implemented by a logic module or software capable of realizing all or part of the functions of the first core network element. The method can be applied to an IMS registration scenario or a call establishment scenario. In the second aspect and its possible implementation, the method is described by taking an example of being executed by a first core network element (such as a UDM network element, a HSS network element, a PCF network element, a PCRF network element). In the method, the first core network element determines first information and sends the first information to a first Internet Protocol Multimedia Subsystem (IMS) network element serving a first terminal device. The first information is used to indicate a first time length for paging the first terminal device or parameter information. The parameter information can be understood as parameter information affecting the time length of paging / calling the first terminal device. The parameter information includes at least one of the following: whether the first terminal device activates a first mechanism / notice, whether the first terminal device has a first capability, a policy of the first mechanism / notice / capability, an access network mode of the first terminal device, a star-facing time length of the first terminal device, etc. A second time length is used to control an operation related to a call of the first terminal device.

[0021] Based on the above scheme, the first core network element sends the first information to the first IMS. Since the first information is used to indicate the first time length for paging the first terminal device or the parameter information. And the parameter information is related to at least one of the following: whether the first terminal device activates an alarm mechanism, a paging policy of the alarm mechanism, an access network mode of the first terminal device, a star-facing time length of the first terminal device, etc. Then the second time length is determined based on the first information, and the second time length is used to control an operation related to a call of the first terminal device. Compared with the scheme in which the IMS determines the time length of the timer based on its own mechanism, the above-mentioned manner considers the paging time length, the alarm mechanism, the access network mode, and the star-facing time length, and other parameter information that may affect the time length of paging / calling the first terminal device when determining the second time length. This can reduce the problem of incorrect termination of the call caused by the second time length being too small. It can also reduce the invalid waiting of the call terminal caused by the second time length being too large.

[0022] Optionally, in a possible implementation of the second aspect, the first information includes the first time length, and the first core network element determines the first information, including: the first core network element determines the first time length based on the parameter information.

[0023] In a possible implementation of the second aspect, the first core network element can obtain the parameter information first, and then determine the first time length according to the parameter information.

[0024] Optionally, in a possible implementation of the second aspect, the first core network element can further receive second information sent by the second core network element, the second information being used to indicate the first time length.

[0025] In this possible implementation, the first core network element can obtain the first time length by receiving the second information sent by the second core network element. This facilitates subsequent setting or starting of the timer based on the second time length according to the first time length, and reduces the risk of call being terminated by mistake or invalid waiting of the second terminal device.

[0026] Optionally, in a possible implementation of the second aspect, the first core network element can further receive parameter information sent by the second core network element.

[0027] In this possible implementation, the first core network element can obtain the parameter information by receiving the parameter information sent by the second core network element. This facilitates subsequent determination of the second time length by the first IMS network element according to the parameter information, and setting or starting of the timer based on the second time length, thereby reducing the risk of call being terminated by mistake or invalid waiting of the second terminal device.

[0028] Optionally, in a possible implementation of the second aspect, the method is applied to a first core network element, the first core network element is a unified data management function (UDM) network element or a policy control function (PCF) network element, and the second core network element is an access and mobility management function (AMF) network element.

[0029] In this possible implementation, the first IMS network element can obtain the first information in an IMS registration process (corresponding to the first core network element being a UDM network element) or a call establishment process (corresponding to the second core network element being a PCF network element), thereby improving the diversity of the manner of obtaining the first information.

[0030] The third aspect of the present application provides a communication method, which is executed by a second IMS network element, or executed by a part of components (such as a processor, a chip, a chip system, a P-CSCF entity or a S-CSCF entity, etc.) in the second IMS network element, or can also be implemented by a logic module or software which can realize all or part of the functions of the second IMS network element. The method can be applied to an IMS registration scenario or a call establishment scenario. In the third aspect and possible implementation manners thereof, the method is described by taking an example of being executed by the second IMS network element (which can also be referred to as a calling IMS). In the method, the second IMS network element sends a call request to a first IMS network element, and receives a second time length sent by the first IMS network element, the second time length is used to control an operation related to a call of a first terminal device, and the second time length is related to parameter information. The parameter information can be understood as parameter information which affects a time length of paging / calling the first terminal device. The parameter information includes at least one of the following: whether the first terminal device activates a first mechanism / indication, whether the first terminal has a first capability, a policy of the first mechanism / indication / capability, an access network mode of the first terminal device, a star-facing time length of the first terminal device, and the like. The second time length is used to control the operation related to the call of the first terminal device.

[0031] Based on the above scheme, since the first information is used to indicate the first time length of paging the first terminal device or the parameter information. And the parameter information is related to at least one of the following: whether the first terminal device activates an alarm mechanism, a paging policy of the alarm mechanism, an access network mode of the first terminal device, a star-facing time length of the first terminal device, and the like. Then the second time length is determined based on the first information, and the second time length is used to control the operation related to the call of the first terminal device. Compared with the scheme in which the IMS determines the time length of the timer based on its own mechanism, the above manner considers the parameter information which may affect the time length of paging / calling the first terminal device when determining the second time length, such as the paging time length, the alarm mechanism, the access network mode, and the star-facing time length, etc. Therefore, the problem of the call being terminated incorrectly due to the second time length being too small can be reduced. Also, the invalid waiting of the call terminal due to the second time length being too large can be reduced.

[0032] Optionally, in a possible implementation manner of the third aspect, the second IMS network element can also send prompt information to the second terminal device, and the prompt information is used to prompt the second terminal device to wait for the call to be connected.

[0033] In this possible implementation manner, the second IMS network element can make the second terminal device wait for the reply of the first terminal device by sending the prompt information to the second terminal device, so as to reduce the communication abnormity caused by the second terminal device estimating too early.

[0034] Optionally, in a possible implementation manner of the third aspect, the operation related to the call of the first terminal device comprises: terminating the call of the first terminal device, or re-sending a call request for calling the first terminal device.

[0035] In the possible implementation manner, the call of the first terminal device can be terminated or the call request for calling the first terminal device can be re-sent through the second time length. Thus, the operation related to the call of the first terminal device is flexibly controlled through the second time length.

[0036] Optionally, in a possible implementation manner of any of the first aspect to the third aspect, the second time length when the first terminal device activates the alert mechanism is different from the second time length when the first terminal device does not activate the alert mechanism.

[0037] In the possible implementation manner, the second time length corresponding to the activation of the alert mechanism is different from the second time length corresponding to the non-activation of the alert mechanism, for example, the second time length corresponding to the activation of the alert mechanism is greater than the second time length corresponding to the non-activation of the alert mechanism, considering the time delay caused by the alert mechanism.

[0038] Optionally, in a possible implementation manner of any of the first aspect to the third aspect, when the first terminal device activates the alert mechanism, the second time length is determined based on a paging strategy of the alert mechanism and / or a star time length.

[0039] In the possible implementation manner, the multiple cases of the parameter information can be combined with each other, for example, when the first terminal device activates the alert mechanism, the second time length can be determined according to the paging strategy and / or the star time length, that is, the time for the first terminal device to respond to the call request is considered from multiple aspects, so as to improve the probability of normal communication between the first terminal device and the second terminal device.

[0040] Optionally, in a possible implementation manner of any of the first aspect to the third aspect, the paging strategies of different alert mechanisms correspond to different second time lengths.

[0041] In the possible implementation manner, the paging strategies of different alert mechanisms correspond to different second time lengths, considering the time delay caused by different paging strategies.

[0042] Optionally, in a possible implementation manner of any of the first aspect to the third aspect, the access network mode of the first terminal device comprises: a satellite mode or a non-satellite mode, and the second time lengths of different access network modes are different.

[0043] In a possible implementation manner, the second time length corresponding to the satellite mode is different from the second time length of the non-satellite mode, for example, the second time length of the satellite mode is greater than the second time length of the non-satellite mode, and the time delay caused by the first terminal device object is considered.

[0044] The fourth aspect of the present application provides a communication apparatus, which is a first IMS network element, or a part of the first IMS network element (for example, a processor, a chip, a chip system, a P-CSCF entity or an S-CSCF entity, etc.), or a logic module or software capable of realizing all or part of the functions of the first IMS network element. The communication apparatus comprises a transceiver unit and a processing unit.

[0045] The transceiver unit is configured to receive first information sent by a first core network element.

[0046] The processing unit is configured to determine a second time length based on the first information.

[0047] The first information is used to indicate a first time length for paging the first terminal device or parameter information. The parameter information can be understood as parameter information affecting the time length for paging / calling the first terminal device. The parameter information comprises at least one of the following: whether the first terminal device activates a first mechanism / indication, whether the first terminal device has a first capability, a policy of the first mechanism / indication / capability, an access network mode of the first terminal device, a satellite access time length of the first terminal device, etc. The second time length is used to control an operation related to a call of the first terminal device.

[0048] Optionally, in a possible implementation manner of the fourth aspect, the operation related to the call of the first terminal device comprises: terminating the call of the first terminal device, or re-sending a call request for calling the first terminal device.

[0049] Optionally, in a possible implementation manner of the fourth aspect, the transceiver unit is further configured to send a call request for calling the first terminal device; and the processing unit is further configured to set / start a timer based on the second time length, and if the timer is expired, terminate the call of the first terminal device or re-send the call request.

[0050] Optionally, in a possible implementation manner of the fourth aspect, the processing unit is specifically configured to determine the second time length based on the first time length, or the processing unit is specifically configured to determine the second time length based on the parameter information.

[0051] Optionally, in a possible implementation manner of the fourth aspect, the transceiver unit is further configured to send the second time length to a second Internet Protocol Multimedia Subsystem (IMS) network element.

[0052] The fifth aspect of the present application provides a communication device, which is a first core network element (a UDM network element or a PCF network element, etc.), or a part of the first core network element (for example, a processor, a chip, a chip system), or a logic module or software capable of realizing all or part of the function of the first core network element. The communication device comprises a transceiver unit and a processing unit.

[0053] The processing unit is configured to determine the first information.

[0054] The transceiver unit is configured to send the first information to a first Internet Protocol Multimedia Subsystem (IMS) network element serving the first terminal device.

[0055] The first information is used to indicate a first time length or parameter information for paging the first terminal device. The parameter information can be understood as parameter information affecting the time length of paging / calling the first terminal device. The parameter information comprises at least one of the following: whether the first terminal device activates a first mechanism / indication, whether the first terminal device has a first capability, a policy of the first mechanism / indication / capability, an access network mode of the first terminal device, a time length of aiming at a star of the first terminal device, etc. The second time length is used to control an operation related to the call of the first terminal device.

[0056] Optionally, in a possible implementation manner of the fifth aspect, the first information comprises the first time length, and the processing unit is specifically configured to determine the first time length based on the parameter information.

[0057] Optionally, in a possible implementation manner of the fifth aspect, the transceiver unit is further configured to receive second information sent by the second core network element, and the second information is used to indicate the first time length.

[0058] Optionally, in a possible implementation manner of the fifth aspect, the transceiver unit is further configured to receive the parameter information sent by the second core network element.

[0059] Optionally, in a possible implementation manner of the fifth aspect, the communication device is the first core network element, the first core network element is a Unified Data Management (UDM) network element or a Policy Control Function (PCF) network element, and the second core network element is an Access and Mobility Management Function (AMF) network element.

[0060] The sixth aspect of the present application provides a communication device, which is a second IMS network element, or a part of the second IMS network element (for example, a processor, a chip, a chip system, a P-CSCF entity or an S-CSCF entity, etc.), or a logic module or software capable of realizing all or part of the function of the second IMS network element. The communication device comprises a transceiver unit.

[0061] The transceiver unit is configured to send a call request to a first IMS network element.

[0062] The transceiver is further configured to receive a second time length sent by the first IMS network element, the second time length being used to control an operation related to the call of the first terminal device, and the second time length being related to parameter information, which can be understood as parameter information affecting the time length of paging / calling the first terminal device. The parameter information includes at least one of the following: whether the first terminal device activates the first mechanism / indication, whether the first terminal device has the first capability, a policy of the first mechanism / indication / capability, an access network mode of the first terminal device, and a time length of aiming at a satellite of the first terminal device. The second time length is used to control the operation related to the call of the first terminal device.

[0063] Optionally, in a possible implementation manner of the sixth aspect, the transceiver is further configured to send prompt information to the second terminal device, the prompt information being used to prompt the second terminal device to wait for the call to be connected.

[0064] Optionally, in a possible implementation manner of the sixth aspect, the operation related to the call of the first terminal device includes: terminating the call of the first terminal device, or re-sending a call request for calling the first terminal device.

[0065] Optionally, in a possible implementation manner of any of the fourth aspect to the sixth aspect, the second time length of the first terminal device in the case of activating the alerting mechanism is different from the second time length of the first terminal device in the case of not activating the alerting mechanism.

[0066] Optionally, in a possible implementation manner of any of the fourth aspect to the sixth aspect, in the case of activating the alerting mechanism, the second time length is determined based on a paging policy of the alerting mechanism and / or a time length of aiming at a satellite.

[0067] Optionally, in a possible implementation manner of any of the fourth aspect to the sixth aspect, the paging policies of different alerting mechanisms correspond to different second time lengths.

[0068] Optionally, in a possible implementation manner of any of the fourth aspect to the sixth aspect, the access network mode of the first terminal device includes: a satellite mode or a non-satellite mode, and the second time lengths of different access network modes are different.

[0069] The seventh aspect of the present application provides a communication device, including at least one processor, the at least one processor being coupled with at least one memory; the at least one memory is used to store programs or instructions; the at least one processor is used to execute the programs or instructions, so that the device implements the method in any of the possible implementation manners of the first aspect.

[0070] The eighth aspect of the present application provides a communication device, comprising at least one processor, the at least one processor being coupled with at least one memory; the at least one memory being configured to store programs or instructions; and the at least one processor being configured to execute the programs or instructions to enable the device to implement the method of any possible implementation of the second aspect.

[0071] The ninth aspect of the present application provides a communication device, comprising at least one processor, the at least one processor being coupled with at least one memory; the at least one memory being configured to store programs or instructions; and the at least one processor being configured to execute the programs or instructions to enable the device to implement the method of any possible implementation of the third aspect.

[0072] The tenth aspect of the present application provides a communication device, comprising at least one logic circuit and at least one input / output interface; the logic circuit being configured to execute the method of any possible implementation of the first aspect.

[0073] The eleventh aspect of the present application provides a communication device, comprising at least one logic circuit and at least one input / output interface; the logic circuit being configured to execute the method of any possible implementation of the second aspect.

[0074] The twelfth aspect of the present application provides a communication device, comprising at least one logic circuit and at least one input / output interface; the logic circuit being configured to execute the method of any possible implementation of the third aspect.

[0075] The thirteenth aspect of the present application provides a communication system, comprising the communication device of any possible implementation of the seventh aspect, the communication device of any possible implementation of the eighth aspect, and the communication device of any possible implementation of the ninth aspect. Or comprising the communication device of any possible implementation of the tenth aspect, the communication device of any possible implementation of the eleventh aspect, and the communication device of any possible implementation of the twelfth aspect.

[0076] The fourteenth aspect of the present application provides a computer readable storage medium, the storage medium being configured to store one or more computer execution instructions, when the computer execution instructions are executed by a processor, the processor executes the method of any possible implementation of any one of the first aspect to the third aspect.

[0077] The fifteenth aspect of the present application provides a computer program product (or computer program), when a computer program in the computer program product is executed by the processor, the processor executes the method in any possible implementation manner of any one of the first aspect to the third aspect.

[0078] The sixteenth aspect of the present application provides a chip or chip system, comprising at least one processor, used for supporting a communication device to implement the method in any possible implementation manner of any one of the first aspect to the third aspect.

[0079] In a possible design, the chip system can further comprise at least one memory, used for storing necessary program instructions and data of the communication device. The chip system can be composed of a chip, or can comprise a chip and other discrete devices. Optionally, the chip system further comprises an interface circuit, which provides program instructions and / or data for the at least one processor.

[0080] The technical effects brought by any one of the fourth aspect to the sixteenth aspect can be referred to the technical effects brought by different design manners of the first aspect to the third aspect, which will not be repeated here. BRIEF DESCRIPTION OF DRAWINGS

[0081] FIG. 1 is a schematic diagram of a communication system provided by the present application;

[0082] FIG. 2A is another schematic diagram of a communication system provided by the present application;

[0083] FIG. 2B is another schematic diagram of a communication system provided by the present application;

[0084] FIG. 3 is a schematic diagram of an architecture of an IMS network provided by the present application;

[0085] FIG. 4 is another schematic diagram of a communication system in a roaming scenario provided by the present application;

[0086] FIG. 5A is a schematic diagram of a satellite communication process in a transparent mode provided by the present application;

[0087] FIG. 5B is a schematic diagram of a satellite communication process in a regenerative mode provided by the present application;

[0088] FIG. 6 is a flow diagram of a communication method provided by the present application;

[0089] FIG. 7 is another flow diagram of a communication method provided by the present application;

[0090] FIG. 8 is another flow diagram of a communication method provided by the present application;

[0091] FIG. 9 is another flow diagram of a communication method provided by the present application;

[0092] Figure 10 is another flow diagram of a communication method in an IMS registration scenario according to the present application;

[0093] Figure 11 is another flow diagram of a communication method in a call setup scenario according to the present application;

[0094] Figures 12 to 14 are several schematic diagrams of a communication apparatus according to the present application. DETAILED DESCRIPTION

[0095] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application.

[0096] First, some terms in the embodiments of the present application will be explained to facilitate understanding by those skilled in the art.

[0097] 1. Configuration and pre-configuration

[0098] In the present application, both configuration and pre-configuration will be used. The configuration refers to that a network device / server sends some parameter configuration information or parameter values to a terminal through a message or signaling, so that the terminal determines the communication parameters or transmission resources according to the values or information. The pre-configuration is similar to the configuration, which can be parameter information or parameter values pre-agreed by the network device / server and the terminal device, or parameter information or parameter values defined in a standard protocol and used by the base station / network device or the terminal device, or parameter information or parameter values pre-stored in the base station / server or the terminal device. The present application does not limit this.

[0099] Further, the values and parameters can be changed or updated.

[0100] 2. In the present application, "for indicating" can include direct indication and indirect indication. When describing that an indication information is for indicating A, it can be understood that the indication information carries A, directly indicates A or indirectly indicates A.

[0101] In the present application, the information indicated by the indication information is referred to as to-be-indicated information. In the specific implementation process, there are many ways to indicate the to-be-indicated information, for example, it can be realized by a direct indication manner, such as indicating by the to-be-indicated information itself or the index of the to-be-indicated information. It can also be realized by an indirect indication manner by indicating other information, wherein the other information and the to-be-indicated information have an association relationship. It can also only indicate a part of the to-be-indicated information, and the other part of the to-be-indicated information is known or agreed in advance. For example, the indication of a specific information can also be realized by means of the arrangement order of each information pre-agreed (for example, defined in a protocol), thereby reducing the indication overhead to a certain extent.

[0102] The to-be-indicated information can be sent together as a whole, or can be sent separately into multiple sub-information, and the sending period and / or sending occasion of the sub-information can be the same or different. The specific sending method is not limited in the present application. The sending period and / or sending occasion of the sub-information can be pre-defined, for example, pre-defined according to a protocol, or can be configured by the transmitting end device to the receiving end device. The 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. The MAC layer signaling includes, for example, MAC CE; the physical layer signaling includes, for example, downlink control information (DCI).

[0103] 3, In the present application, "sending" and "receiving" represent the direction of signal transmission. In the present application, entity A sends information to entity B, which can be A directly sending to B, or A indirectly sending to B through other entities. Similarly, entity B receives information from entity A, which can be entity B directly receiving information sent by entity A, or entity B indirectly receiving information sent by entity A through other entities. Entity A and B in the present application can be RAN nodes or terminals, or modules inside RAN nodes or terminals. The sending and receiving of information can be the information interaction between RAN nodes and terminals, for example, the information interaction between base stations and terminals; the sending and receiving of information can also be the information interaction between two RAN nodes, for example, the information interaction between CU and DU; the sending and receiving of information can also be the information interaction between different modules in one device, for example, the information interaction between the terminal chip and other modules of the terminal, or the information interaction between the base station chip and other modules in the base station. "Sending" can also be understood as the "output" of the chip interface, for example, the baseband chip outputs 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 output of the baseband part to the radio frequency part inside the device, and "receiving" can also be understood as the radio frequency part receiving the output information of the baseband part.

[0104] 4、The terms "system" and "network" in the embodiments of the present application can be used interchangeably. "At least one" means one or more, and "multiple" means two or more. The "and / or" describes the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B can represent the cases of A alone, A and B together, and B alone, where A and B can be singular or plural. The character " / " generally represents an "or" relationship between the associated objects before and after it. "At least one of the following" or similar expressions means any combination of these items, including any combination of single or multiple items. For example, "at least one of A, B and C" includes A, B, C, AB, AC, BC or ABC. In addition, unless otherwise specified, the ordinal numbers "first", "second", etc. mentioned in the embodiments of the present application are used to distinguish a plurality of objects, and are not used to limit the order, time sequence, priority or importance of the plurality of objects.

[0105] Referring to FIG. 1, a system architecture provided by the present application is shown. The system architecture includes a terminal device, a radio access network (RAN) device, a core network (CN) and a digital network (DN).

[0106] The CN is responsible for maintaining the subscription data of the mobile network, managing the network elements of the mobile network, and providing the terminal device with functions such as session management, mobility management, policy management and security authentication. When the terminal device is attached, the CN provides the terminal device with network access authentication; when the terminal device has a service request, the CN allocates network resources to the terminal device; when the terminal device moves, the CN updates the network resources of the terminal device; when the terminal device is idle, the CN provides the terminal device with a fast recovery mechanism; when the terminal device is detached, the CN releases the network resources of the terminal device; when the terminal device has service data, the CN provides the terminal device with data routing functions, such as forwarding uplink data to the digital network; or receiving downlink data of the terminal device from the digital network and forwarding it to the radio access network, so as to send it to the terminal device. Further, the network elements included in the core network will be different according to the applicable communication system, which will be described exemplarily in combination with FIG. 2A and FIG. 2B.

[0107] The radio access network can be understood as an access network that realizes the access network function based on wireless communication technology. The radio access network can manage wireless resources and provide access services for the terminal device, thereby completing the forwarding of control signals and user data between the terminal device and the core network.

[0108] The DN is a data network providing service for the terminal device. Generally, the client is located at the terminal device, and the server is located at the data network. The data network can be a private network, such as a local area network, or an external network not controlled by an operator, such as the Internet, or a dedicated network jointly deployed by operators, such as a network providing IP multimedia subsystem (IMS) services. That is, the data network is used to provide a network for transmitting data. For example, a network of an operator service, the Internet, a service network of a third party, and the like.

[0109] In an embodiment of the present application, the terminal device can be a wireless terminal device capable of receiving scheduling and indication information of a network device. The wireless terminal device can be a device providing voice and / or data connectivity to a user, or a handheld device having a wireless connection function, or another processing device connected to a wireless modem.

[0110] Optionally, the terminal device can be various communication kits (a kit can include, for example, an antenna, a power supply template, a cable, and a Wi-Fi module, etc.) with wireless communication functions, and the terminal device can also be a communication module with satellite communication functions, a satellite phone or its components, a very small aperture terminal (VSAT), etc. The terminal device can be a mobile terminal device, such as a mobile phone (or called "cellular" phone, mobile phone), a computer, and a data card, etc. For example, it can be a portable, pocket-sized, handheld, computer-built-in, or vehicle-mounted mobile device that exchanges voice and / or data with a wireless access network. For example, a personal communication service (PCS) phone, a cordless phone, a session initiation protocol (SIP) phone, a wireless local loop (WLL) station, a personal digital assistant (PDA), a tablet computer (Pad), a computer with wireless transceiver function, etc. The wireless terminal device can also be called a system, a subscriber unit, a subscriber station, a mobile station, a remote station, an access point, a remote terminal, an access terminal, a user terminal, a user agent, a subscriber station, a customer premises equipment, a terminal, a user equipment, a mobile terminal, a drone, etc. The terminal device can also be a wearable device and a next-generation communication system, for example, a terminal device in a future communication system or a terminal device in a future evolved public land mobile network (PLMN), etc. Of course, the terminal device in this application can also refer to a chip, a modem, a system on a chip (SoC), or a communication platform that can include a radio frequency (RF) part, etc. in the device mainly responsible for the relevant communication functions.

[0111] The network device can be a device in a wireless network, for example, the network device can be a radio access network (RAN) node (or device) that accesses a terminal device to a wireless network, which can also be referred to as a base station. Currently, some examples of the RAN device are: a new generation base station in a future communication system, a transmission reception point (TRP), an evolved Node B (eNB), a radio network controller (RNC), a Node B (NB), a base station controller (BSC), a base transceiver station (BTS), a home base station (for example, a home evolved Node B or a home Node B, HNB), a base band unit (BBU), or a wireless fidelity (Wi-Fi) access point (AP), etc. In addition, in a network structure, the network device can include a centralized unit (CU) node, or a distributed unit (DU) node, or a RAN device including the CU node and the DU node.

[0112] In some implementations, the network device can also include a satellite, an airplane, a drone, and a ground station device connected with the satellite, the airplane, and the drone, etc.

[0113] In the embodiments of the present application, the network device can send configuration information (for example, carried in a scheduling message and / or an indication message) to the terminal device, and the terminal device further performs network configuration according to the configuration information, so that the network configuration between the network device and the terminal device is aligned; or, through the preset network configuration of the network device and the preset network configuration of the terminal device, the network configuration between the network device and the terminal device is aligned. Specifically, "alignment" means that when there is an interactive message between the network device and the terminal device, the two devices are consistent in understanding the carrier frequency of the interactive message transmission and reception, 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.

[0114] In addition, in other possible cases, the network device can be other devices that provide wireless communication functions for the terminal device. The embodiments of the present application do not limit the specific technology and specific device form of the network device.

[0115] In the embodiments of the present application, the apparatus for implementing the function of the network device can be the network device, or can be an apparatus capable of supporting the network device to implement the function, for example, a chip system, which can be installed in the network device. In the technical solutions provided in the embodiments of the present application, the apparatus for implementing the function of the network device is taken as an example of the network device to describe the technical solutions provided in the embodiments of the present application.

[0116] Optionally, logically, the system architecture shown in FIG. 1 can be divided into a user plane and a control plane, the control plane is responsible for the management of the mobile network, and the user plane is responsible for the transmission of service data. In FIG. 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.

[0117] It can be understood that the connection lines in FIG. 1 are only examples in some scenarios, and in future communication systems, for example, the terminal device can also directly communicate with the core network. For another example, the radio access network device can also directly communicate with the data network. For another example, the terminal device can also directly communicate with the data network.

[0118] In a possible implementation manner, the system architecture shown in FIG. 1 can be specifically a 4G system architecture as shown in FIG. 2A. The network elements / devices in the 4G system architecture include: a terminal device (for example, UE in FIG. 2A), a mobility management entity (MME), a serving GPRS support node (SGSN), a home subscriber server (HSS), a serving gateway (SGW), a packet data network gateway (PDN gateway, PGW), a policy and charging rules function (PCRF) entity, an evolved universal terrestrial radio access network (E-TURAN), and the like.

[0119] Wherein, the E-UTRAN includes a plurality of evolved base stations (eNodeB), the eNodeB are interconnected with each other through an X2 interface, the eNodeB and the evolved packet core (EPC) are interconnected through an S1 interface, and the eNodeB and the terminal device are interconnected through an LTE-Uu.

[0120] The main functions of the MME include supporting NAS messages and their security, managing a track area (TA) list, selecting a P-GW and an S-GW, selecting an MME during a cross-MME handover, selecting an SGSN during a handover to a 2G / 3G access system, authenticating a terminal device, performing roaming control and bearer management, and performing mobility management between core network nodes of different access networks of the 3rd generation partnership project (3GPP).

[0121] The S-GW is a gateway that terminates an E-UTRAN interface, and the main functions thereof include serving as a local anchor point during an inter-eNodeB handover and assisting in performing a base station reordering function, serving as a mobility anchor point during a handover between different 3GPP access systems, performing data packet routing and forwarding, performing packet marking in an uplink and a downlink transmission layer, and performing inter-operator charging.

[0122] The P-GW is a gateway that terminates an SGi interface for a PDN, and if a terminal device accesses multiple PDNs, the terminal device will correspond to one or more P-GWs. The main functions of the P-GW include a terminal device-based packet filtering function, a terminal device internet protocol (IP) address allocation function, performing data packet transfer level marking in an uplink, performing uplink and downlink service level charging and service level threshold control, and performing uplink and downlink rate control based on services.

[0123] The HSS is a database for storing terminal device subscription information, and one or more HSSs can be included in a home network. The HSS is responsible for storing information related to a terminal device, such as terminal device identification, numbering, and routing information, security information, location information, profile information, and the like.

[0124] The SGSN can be used for signaling interaction between 2G / 3G and E-UTRAN 3GPP access networks during a handover, including selection of a P-GW and an S-GW, and selection of an MME for a terminal device that is handed over to an E-UTRAN 3GPP access network.

[0125] The PCRF entity terminates on the Rx interface and the Gx interface. In a non-roaming scenario, there is only one PCRF associated with a terminal device's IP-connectivity access network (IP-CAN) session in the home public land mobile network (HPLMN). In a roaming scenario and when traffic steering is local, there can be two PCRFs associated with a terminal device's IP-CAN session.

[0126] In another possible implementation manner, the system architecture shown in FIG. 1 can be specifically the 5G system architecture as shown in FIG. 2B. The network elements / devices in the 5G system architecture include: a terminal device (for example, UE in FIG. 2B), a DN, a RAN, a network slice selection function (NSSF) network element, a network exposure function (NEF) network element, a network repository function (NRF) network element, a policy control function (PCF) network element, a unified data management (UDM) network element, an application function (AF) network element, an authentication server function (AUSF) network element, an access and mobility management function (AMF) network element, a session management function (SMF) network element, a service communication proxy (SCP) network element, and a user plane function (UPF) network element.

[0127] Optionally, the system architecture shown in FIG. 2B can also include other network elements not shown in the following figures, for example, a network slice-specific authentication and authorization function (NSSAAF) network element, a network slice admission control (NSACF) network element, a unified data repository (UDR) network element, etc., without limitation.

[0128] The following introduces several key network elements included in the CN:

[0129] 1. AMF network element: responsible for user mobility management, including mobile state management, allocation of user temporary identity, authentication and authorization of users.

[0130] 2. UDM network element: responsible for managing subscription data, and responsible for notifying the corresponding network element when the subscription data is modified.

[0131] 3. NSSF network element: responsible for network slice selection.

[0132] 4. SMF network element: responsible for user plane (UP) network element selection, UP network element reselection, internet protocol (IP) address allocation, and responsible for session establishment, modification and release, quality of service (QoS) control.

[0133] 5. AUSF network element: mainly responsible for network security, used to generate keys, implement bidirectional authentication for UEs, and implement 3GPP and non-3GPP access authentication.

[0134] 6. NEF network element: open the capabilities of various network elements, convert internal and external information, and used for edge computing scenarios.

[0135] 7. PCF network element: mainly used for managing policy rules, managing user subscription information, etc.

[0136] 8. UDR network element: stores and retrieves subscription data, policy data, and public architecture data, etc., for UDM, PCF, and NEF to obtain related data. UDR can have different data access authentication mechanisms for different types of data such as subscription data and policy data, to ensure the security of data access. UDR can return a failure response with appropriate reason value for illegal service operation or data access request.

[0137] 9. NRF network element: responsible for the registration and discovery function of the network element, and maintains the information of the network element, for example, the instance identifier, type, PLMN, slice-related identifier, IP address or fully qualified domain name (FQDN) of the network element, the capability of the network element, supported services, etc.

[0138] 10. AF network element: mainly used for sending application impact data routing information to the network, interacting with the policy framework through the network exposure function network element for policy control, etc.

[0139] 11. UPF network element: interconnecting, packet routing and forwarding, and data packet detection of Protocol Data Unit (PDU) sessions and data networks.

[0140] It can be understood that the network architecture to which the embodiments of the present application are applicable is not limited to FIG. 2A or FIG. 2B, and any network architecture capable of realizing the functions of the above-mentioned network elements is applicable to the embodiments of the present application. In addition, the network elements included in the above-mentioned core network can be independent devices or can be integrated into the same device to realize different functions, and the present application does not limit the specific form of the above-mentioned network elements.

[0141] The present application can be applied to a long term evolution (LTE) system, a new radio (NR) system, or a new radio vehicle to everything (NR V2X) system; can also be applied to a system in which LTE and 5G are hybrid networked; or a device-to-device (D2D) communication system, a machine to machine (M2M) communication system, an Internet of Things (IoT), or a drone communication system; or a communication system supporting multiple wireless technologies, such as supporting LTE technology and NR technology; or a non-ground communication system, such as a satellite communication system, a high-altitude communication platform, etc. In addition, the communication system can also be applied to a narrow band-internet of things (NB-IoT) system, an enhanced data rate for GSM evolution (EDGE) system, a wideband code division multiple access (WCDMA) system, a code division multiple access 2000 (CDMA2000) system, a time division-synchronization code division multiple access (TD-SCDMA) system, and a future-oriented communication technology.

[0142] It should be noted that the above naming is only defined for the purpose of distinguishing different functions, and should not constitute any limitation on the present application. The present application does not exclude the possibility of using other names in 5G networks and future other networks. For example, in future communication networks, part or all of the above-mentioned network elements can continue to use the terms in 5G, or other names may be used, etc. The interface names between the network elements in FIGS. 1 to 2B are only an example, and the names of the interfaces in the specific implementation can be other names, which are not limited in the present application. In addition, the names of the messages (or signaling) transmitted between the above-mentioned network elements are also only an example, and do not constitute any limitation on the functions of the messages themselves.

[0143] It can be understood that the above FIGS. 2A and 2B are only two examples of the system architecture of FIG. 1, and in actual applications, the system architecture shown in FIG. 1 can also have other forms, which are not limited here.

[0144] Exemplarily, the DN in the above FIG. 1 to FIG. 2B can be an IMS network. The IMS is one of the core technologies of network communication, and can meet the demand of terminals for more novel and diversified multimedia services. The IMS is an important way to solve the integration of mobile and fixed networks, and to introduce triple convergence of voice, data and video, and other differentiated services. The IMS network will be briefly introduced below in combination with FIG. 3.

[0145] FIG. 3 is a schematic diagram of an architecture of an IMS network. As shown in FIG. 3, the IMS network can include a telephony application server (TAS), a proxy-call session control function (P-CSCF) entity, a serving-call session control function (S-CSCF) entity of a service type, 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, and the like.

[0146] The TAS provides voice and multimedia call services for fixed mobile convergence network users, supports related basic services and supplementary services, integrates fixed mobile convergence services on the same platform, and provides unified service experience for fixed network and mobile network users.

[0147] The S-CSCF entity is a central node of the IMS network, and is responsible for user registration, authentication, session, routing and service triggering.

[0148] The P-CSCF entity is an entry node for session initiation protocol (SIP) users to access the IMS network, and is mainly responsible for forwarding SIP signaling between SIP users and a home network.

[0149] The IMS-AGW is an IMS access gateway, and is mainly responsible for media plane interworking of a user-network interface.

[0150] The TrGW is an IMS interworking gateway, and is responsible for media plane interworking of a network-network interface.

[0151] The IBCF entity is mainly used to realize the interworking of the control plane of the IMS network and other IMS networks. For example, the calling party is the IMS network of China Mobile, and the called party is the IMS network of China Telecom. When the calling user is an IMS user and the called user is a circuit service (CS) network user, the BGCF entity is responsible for selecting an MGCF entity to the CS network.

[0152] The MGCF entity is mainly used to realize the interworking of the control plane of the IMS network and other non-IP networks (such as a public switched telephone network (PSTN)).

[0153] It can be understood that, in addition to the IMS network element, other networks (such as CS or IMS) can also be collectively referred to as a B party as a calling party or a called party in a real-time audio / video communication process.

[0154] Further, the communication system in the roaming scenario combined with the system architecture shown in FIG. 2A or FIG. 2B can be as shown in FIG. 4. The communication system mainly includes two parts, namely, a visited public land mobile network (VPLMN) and a home public land mobile network (HPLMN). The VPLMN can also be referred to as a visited public land mobile network, and the HPLMN can also be referred to as a local public land mobile network, a local public land mobile network, a home public land mobile network, etc., and the specific embodiments are not limited here.

[0155] For example, in a roaming scenario, a roaming routing (also referred to as local breakout (LBO)) mode is taken as an example. The VPLMN in the above system architecture can include at least one of the following: a terminal device, an evolved packet system (EPS) / 5th generation system (5GS), a V-PCRF / V-PCF, etc. The HPLMN can include at least one of the following: an IMS AGW, an MRFP, an H-PCRF, a P-CSCF, an S-CSCF, etc. The EPS can refer to the description of the CN in the foregoing FIG. 2A, and the 5GS can refer to the description of the CN in the foregoing FIG. 2B.

[0156] Wherein, the P-CSCF is the first access point in the IMS network, which can accept the request and forward the request internally to a service or up. The S-CSCF performs session control services for the UE, which can maintain the session state according to the needs of the network operator to support services.

[0157] It can be understood that the interface types between the two network elements (or devices) in FIG. 4 are marked, such as: the P-CSCF interacts with the H-PCRF through the Rx interface, and such as: the P-CSCF interacts with the S-CSCF through the Mx interface. The specific principles of each interface type can refer to the prior art, which will not be described here.

[0158] It can be understood that FIG. 4 is only an exemplary description of the LBO mode in the roaming scenario, and in actual application, the scheme provided by the embodiments of the present application can also be applicable to the home routing (HR) mode in the roaming scenario, and can also be applicable to the mode in the non-roaming scenario, etc., which is not limited here. For example, for the non-roaming scenario, the difference is that the EPS / 5GS in FIG. 4 are located in the HPLMN, and there is no V-PCRF / V-PCF.

[0159] In addition, the technical scheme of the embodiments of the present application can also be applicable to a communication system that integrates ground communication and satellite communication, which can also be referred to as a non-terrestrial network (NTN) communication system. In other words, the RAN in FIGS. 1 to 2B can include a ground base station, wherein the ground base station can include a TN cell (i.e., the signals of the TN cell can be transmitted and received through the ground base station); and the RAN can also include a non-ground base station, taking a satellite as an example, the satellite can include an NTN cell (i.e., the signals of the NTN cell can be transmitted and received through the satellite). Wherein, the ground 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 developed from the 5G communication system, etc., which is not limited here.

[0160] Wherein, compared with the traditional mobile communication system, the satellite communication has wider coverage, the communication cost is independent of the transmission distance, and can overcome natural geographical obstacles such as oceans, deserts, and mountains. In order to overcome the shortcomings of the traditional communication network, the satellite communication can be an effective supplement to the traditional network. It is generally believed that compared with ground network communication, non-terrestrial network communication has different channel characteristics, such as large transmission delay and large Doppler frequency offset.

[0161] Optionally, according to the difference of orbit height, satellite communication systems can be divided into three kinds as follows: geostationary earth orbit (GEO) satellite communication system, also known as synchronous orbit satellite system; medium earth orbit (MEO) satellite communication system and low earth orbit (LEO) satellite communication system. For example, the round-trip delay of GEO satellite communication is 238-270 milliseconds (ms). The round-trip delay of LEO satellite communication is 8-20 ms. In addition, the NTN system can also include highly elliptical orbiting (HEO) satellites, high altitude platform station (HAPS) communication systems and other aerial network devices, which are not limited here.

[0162] Among them, GEO satellite is also known as geostationary satellite, and the orbit height can be 35786 kilometers (km). The main advantage is that it is relatively stationary on the ground and provides a large coverage area. However, the disadvantages of GEO satellite orbit satellites are relatively prominent: such as the distance from the earth is too large, which requires a large diameter antenna; its transmission delay is large, about 0.5 seconds, which cannot meet the demand of real-time service; at the same time, its orbit resources are relatively scarce, the launch cost is high and it cannot provide coverage for the polar regions. MEO satellite, with an orbit height of 2000-35786 km, has a relatively small number of satellites to achieve global coverage, but its transmission delay is higher than that of LEO satellite, and it is mainly used for positioning and navigation. In addition, the orbit height of 300-2000 km is called low earth orbit (LEO). LEO satellite has a lower orbit height than MEO and GEO, smaller data propagation delay, less power loss, and relatively lower launch cost. Therefore, LEO satellite communication network has made great progress in recent years and has attracted attention.

[0163] In addition, satellite devices can be divided into transparent mode (or transparent mode) and regenerative mode according to the working mode.

[0164] For example, FIG. 5A is an example of a transparent mode (or transparent mode) (transparent payload) of an NTN communication system combined with an IMS network. The system architecture in this example includes a terminal device, a satellite, a gateway station (also known as a gateway station, a ground station, an earth station, etc.), a base station, a core network and an IMS network.

[0165] Specifically, the satellite and the gateway station can act as a relay for the terminal device and the base station to communicate, and can transparently transmit signals between the satellite and the terminal device. For example, the gateway station can access the core network through the base station, and then access the IMS network. The satellite in the transparent transmission mode only performs transparent forwarding. In the example of FIG. 5A, each network element / device can refer to the description of the foregoing system architecture, and will not be described here.

[0166] For example, FIG. 5B is an example of a regenerative mode in an NTN communication system combined with an IMS network. The system architecture in this example includes a terminal device, a satellite (a “base station on satellite”) gateway station, a core network, and an IMS network. Specifically, the satellite in the regenerative mode needs to have all or part of the functions of the base station. In the example of FIG. 5B, each network element / device can refer to the description of the foregoing system architecture, and will not be described here.

[0167] It should be understood that the number of devices / network elements in FIGS. 1-5B is only an example, and in actual applications, the number of devices / network elements included in each of the above systems is not limited here.

[0168] In satellite communication, the terminal device is far away from the satellite, and the link budget is low. In particular, when the user puts the terminal device in the pocket or bag, the antenna of the terminal device cannot be aligned with the satellite, which can cause the terminal device to fail to normally transmit and receive information. For example, when the user needs to answer the phone (i.e., a called scenario), the terminal device fails to receive the paging message sent by the network, resulting in a call failure.

[0169] To solve the above call failure problem, an enhanced paging mechanism or notification mechanism is considered to enable the terminal device to receive the corresponding message when the signal is poor or the link budget is poor. After the terminal device receives the corresponding information, the terminal device can perform a star operation / move to a position with better signal, thereby ensuring the completion of the subsequent communication process.

[0170] Therefore, after introducing the enhanced paging mechanism or notification mechanism, how to further improve the communication experience of the user is a hot issue for discussion.

[0171] To solve the above technical problems, the application provides a communication method and related device, a first IMS network element controls operations related to a call of a first terminal device through a second time length, and determines the second time length considering an enhanced paging mechanism / notification mechanism, for example, when determining the second time length, the first time length required when calling the terminal device through the enhanced paging mechanism / notification mechanism or parameter information related to the enhanced paging mechanism / notification mechanism needs to be considered, which can reduce problems such as the call being terminated incorrectly (the IMS network element times out without receiving a response of the called terminal, but actually the core network is still paging the called terminal through the enhanced paging mechanism / notification mechanism) or invalid waiting of the calling terminal (the IMS network element is still waiting for the response of the called terminal, but actually the paging of the called terminal by the core network has failed) due to the mismatch between the second time length and the enhanced paging mechanism / notification mechanism.

[0172] For the convenience of description, the subsequent description of the network element in the core network device in the embodiments of the application is described taking the 5G communication system as an example. If it is applied to the 4G communication system, the functions of the UDM network element involved subsequently can be performed by the HSS network element in the 4G, the function of the PCF network element can be performed by the PCRF network element in the 4G, the function of the AMF network element can be performed by the MME network element in the 4G, and the like. The description of the core network network elements in the 4G and the 5G can refer to the description in the foregoing FIG. 2A and FIG. 2B, which will not be described here.

[0173] In addition, the IMS network element (for example, the first IMS network element serving the called terminal device, the second IMS network element serving the calling terminal device) in the embodiments of the application can be understood as a single network element (for example, the IMS network element is a P-CSCF or an S-CSCF) in the IMS network, or can be understood as a combination of multiple network elements (for example, the IMS network element includes a P-CSCF and an S-CSCF) in the IMS network, and the like, which is not limited specifically here.

[0174] Please refer to FIG. 6, a flowchart of a communication method provided by an embodiment of the present application is shown, which can include steps 601 to 603. The steps 601 to 603 can be executed by a communication device, or by some components (such as a processor, a chip or a chip system, etc.) in the communication device, or by a logic module or software capable of realizing all or part of the functions of the communication device. Hereinafter, the steps 601 to 603 are described by taking the execution by the communication device as an example. The processes executed by a single execution subject in the steps 601 to 603 can also be divided into processes executed by multiple execution subjects, which can be logically and / or physically separated. For example, in the case where the communication device is a first core network element, the processes executed by the communication device can be divided into processes executed by at least one of an AMF, an SMF, a UPF, a UDM, a PCF, etc. For another example, in the case where the communication device is an access network device, the processes executed by the communication device can be divided into processes executed by at least one of a CU, a DU, a RU, etc. For another example, in the case where the communication device is an IMS network element (such as a first IMS network element or a second IMS network element), the processes executed by the communication device can be divided into processes executed by at least one of a P-CSCF, an S-CSCF, etc. The method can be applied to any one of the system architectures shown in FIGS. 1 to 5B, and the specific embodiments are not limited herein.

[0175] For the convenience of description, in the present application, the IMS serving the called terminal is referred to as a first IMS, the IMS serving the calling terminal is referred to as a second IMS, the called terminal device is referred to as a first terminal device, and the calling terminal device is referred to as a second terminal device. The steps 601 to 603 are described in detail as follows.

[0176] In step 601, a first core network element determines first information.

[0177] The first core network element determines the first information, which is used to indicate a first time length for paging the first terminal device and / or parameter information, etc. The first time length and the parameter information are described in detail as follows.

[0178] In the first case, the first information is used to indicate the first time length.

[0179] The first time length in the embodiments of the present application is related to the paging of the first terminal device. The first time length can be understood as the time length for paging the first terminal device. Paging the first terminal device can be understood as sending a message to the first terminal device through an enhanced paging mechanism or a notification mechanism. For example, the first time length is the time length required for paging the first terminal device. For another example, the first time length is the maximum time length required for paging the first terminal device. For another example, the first time length is the paging time length of the first terminal device, etc. The explanation of the first time length is not limited herein, as long as the first time length is related to the paging of the first terminal device.

[0180] In this case, the first core network element determines the first time length in at least one of the following manners: the first core network element determines the first time length according to the parameter information (which will be described in combination with the parameter information in the second case, and will not be described here), the first core network element sets the first time length according to actual needs (such as scheduling needs, service needs, etc.), the first core network element sets the first time length according to the configuration information of the first terminal device, the first core network element receives the first time length sent by other devices, the first core network element retrieves the historical paging information (containing the paging time length) of the first terminal device from the database, etc. The specific manners are not limited here. It can be understood that the above-mentioned manners can be implemented alone or in combination, and the specific manners are not limited here.

[0181] Optionally, the first time length can also be related to subsequent parameter information. Alternatively, for the manner in which the first core network element determines the first time length according to the subsequent parameter information, the relationship between the first time length and the parameter information or how to determine the first time length according to the corresponding parameter information will be described in each case of the parameter information, and will not be described here.

[0182] In the second case, the first information is used to indicate the parameter information.

[0183] The parameter information in the embodiments of the present application can be understood as the parameter information related to the call or paging of the first terminal device. Alternatively, it can be understood as the parameter information affecting the time length of paging / calling the first terminal device.

[0184] The parameter information includes at least one of the following: whether the first terminal device activates the first mechanism / notice, whether the first terminal has the first capability, the strategy of the first mechanism / notice / capability, the access network mode of the first terminal device, the star facing time length of the first terminal device, etc. The following will be described respectively:

[0185] 1. Whether the first terminal device activates the first mechanism / notice, and whether the first terminal has the first capability.

[0186] In the embodiments of the present application, the first mechanism / notification can be understood as a mechanism / notification related to the call or paging of the first terminal device, and can also be understood as a mechanism / notification that can affect the duration of the call / paging of the first terminal device. The specific name of the first mechanism / notification can be, for example, an Alert mechanism, an enhanced call mechanism, an enhanced call notification, an enhanced paging mechanism, an enhanced paging notification, a resilient notification, a resilient notification, etc. The specific name is not limited in the present application. Similarly, the first capability can be understood as a capability related to the call or paging of the first terminal device, and can also be understood as a capability that can affect the duration of the call / paging of the first terminal device. The specific name of the first capability can be, for example, an Alert capability, an enhanced call capability, an enhanced paging capability, a resilient capability, etc. The specific name is not limited in the present application. For the convenience of description, only the Alert mechanism is used to represent the first mechanism / notification, and the Alert capability is used to represent the first capability for example in the subsequent description.

[0187] For example, the first terminal device activating the Alert mechanism can be understood as that the first terminal device can start monitoring or detecting an Alert message when certain conditions are met, such as poor signal or poor link budget (for example, the received signal strength and / or signal quality is lower than a certain threshold) or low receiver power. The Alter message is used to prompt the first terminal device that there is a call request, or to indicate that the first terminal device has an incoming call, or to indicate that the network fails to page the first terminal device, or to prompt the first terminal device that there is a missed call, etc. After receiving the Alert message, the first terminal device can perform the star operation / move to a better signal position, thereby ensuring the completion of the subsequent communication process. The first terminal having the first capability can be understood as that the first terminal has the capability of monitoring or detecting the Alert message. It can be understood that when the first terminal has the first capability, the terminal can activate the alert mechanism to monitor or detect the alert message.

[0188] In addition, whether the first terminal device activates the first mechanism / notification can be understood as whether the first terminal device itself activates the first mechanism / notification at the terminal side, i.e., whether the first terminal device starts a mechanism of monitoring or detecting an Alert message when a signal is poor or a link budget is poor or a receiver power is low. It can also be understood as whether the network device (including a core network device or an access network device) activates the first mechanism / notification for the first terminal device at the network side, i.e., whether the network device pages or calls the first terminal through the first mechanism / notification. For example, if the first terminal device has activated the first mechanism / notification, the first terminal device can receive relevant information / notification through the first mechanism / notification. For another example, if the first terminal device has activated the first mechanism / notification or the core network activates the first mechanism / notification for the first terminal device, the core network (for example, a second core network element) can send relevant information / notification through the first mechanism / notification. It should be understood that it is meaningful for the core network to call the first terminal device through the first mechanism / notification only when the first terminal device starts to monitor or detect the Alert message.

[0189] In the embodiments of the present application, there are various ways for the first core network element to determine whether the first terminal device activates the first mechanism / notification.

[0190] In a possible implementation manner, the first core network element determines whether the first terminal device activates the Alert mechanism according to the capability information reported by the first terminal device. For example, the first terminal device sends registration request information (registration request) to a second core network element (for example, an AMF element) in the process of registering the network. Correspondingly, the AMF element receives the registration request information sent by the first terminal device. The registration request information includes or is used to indicate the capability information of the first terminal device. The capability information is used to indicate whether the first terminal device has the capability of receiving the Alert message, or is used to indicate whether the first terminal device supports paging enhancement, or is used to indicate whether the first terminal device supports flexible notification, etc. After the core network device receives the registration request information, it can determine whether to activate the alert mechanism according to the strategy. The strategy includes at least one of the following: the capability information reported by the first terminal device, whether the first terminal device subscribes to the Alert service function of the network, whether there is an access network device (for example, a base station) supporting the Alert capability in the registration area of the first terminal device, and the load condition of the network performing paging, etc.

[0191] In another possible implementation manner, the first core network element determines whether the first terminal device activates the Alert mechanism according to subscription information of the first terminal device. For example, the first terminal device subscribes to the Alert service to the network. The AMF element can query the subscription information of the first terminal device from the UDM element. If the subscription information of the first terminal device stored in the UDM element includes the Alert service, the AMF element can query the subscription information of the first terminal device from the UDM element, and determine that the first terminal device subscribes to the Alert service. The first terminal device can subscribe to the Alert service in various ways. For example, the first terminal device can subscribe to the Alert service by separate subscription. For another example, the first terminal device can also subscribe to the Alert service by default when subscribing to the NTN service, and the like. The subscription can be determined according to the operator policy or actual needs, and is not limited here.

[0192] Of course, the two cases described above can also be combined. Specifically, the capability information reported by the terminal device indicates that the terminal device has the first capability, and the subscription information of the terminal device includes the subscription related to the first mechanism / notification. The core network can activate the first mechanism / notification for the terminal device.

[0193] It can be understood that the first duration of the first terminal device under the activated Alert mechanism is different from the first duration of the first terminal device under the unactivated Alert mechanism. For example, the first duration under the activated Alert mechanism is greater than the first duration under the unactivated Alert mechanism.

[0194] For example, in the case where the parameter information includes whether the first terminal device activates the first mechanism / notification, the first core network element determines the first duration according to whether the first terminal device activates the first mechanism / notification. Specifically, the first core network element can first obtain a first association relationship, which is used to represent the association relationship between the first terminal device activating the alert mechanism and the first duration. Or the first association relationship is used to represent the association relationship between the first terminal device not activating the alert mechanism and the first duration.

[0195] For example, the first association relationship can be as shown in Table 1:

[0196] Table 1

[0197] Wherein, the first duration of the first terminal device under the activated alert mechanism is T1, and the first duration of the first terminal device under the unactivated alert mechanism is T2. Optionally, T1 is greater than T2.

[0198] 2, the policy of the first mechanism / notification.

[0199] The policy of the first mechanism / notification can be understood as a policy related to the first mechanism / notification. The policy can affect the duration of calling / paging the first terminal device. The specific name of the policy can be, for example, a call policy, a paging policy, or a notification policy, and the specific name is not limited in the present application. The paging policy is exemplarily described in the following.

[0200] Optionally, the policy can be related to the type of paging / notification, the number of paging messages / notifications, and the like. The type of paging / notification can include paging and Alert paging / notification. The number of paging messages / notifications can include the number of paging messages / notifications and / or the number of Alert messages / notifications.

[0201] In addition, the policy of the first terminal device activating the first mechanism / notification can be understood as follows. On the terminal side, the first terminal device itself activates which policy or policies corresponding to the first mechanism / notification when the first mechanism / notification has been activated, that is, the first terminal device uses which policy to monitor or detect the Alert message mechanism when the signal is poor or the link budget is poor or the receiver power is low. It can also be understood that on the network side, the network device (including the core network device or the access network device) uses which policy to send the message corresponding to the first mechanism / notification to the first terminal device. For example, if the first terminal device has activated policy 1 of the first mechanism / notification, it can receive related information / notification through policy 1. For another example, if the first terminal device has activated policy 1 of the first mechanism / notification, or the core network device activates policy 1 of the first mechanism / notification for the first terminal device, the core network device can send related information / notification through policy 1 of the first mechanism / notification, and the like. It should be understood that it only makes sense for the core network device to call the first terminal device through policy 1 when the first terminal device activates policy 1.

[0202] Exemplarily, the above policy is related to at least one of the following: only performing Alert paging / notification (or understood as the terminal device receiving the Alert message and not receiving the Paging message) when paging / calling the terminal device, performing paging and Alert paging / notification, the number of paging messages / notifications, the number of Alert messages / notifications, and the like.

[0203] It can be understood that the above policy can be configured by the core network, can be selected by the user to which the first terminal device belongs, can be pre-set by the operator, can be stored in the memory of the device, can be obtained from other devices, and the like. The specific implementation is not limited herein.

[0204] The policy is exemplarily described below.

[0205] For example, when the network needs to page the first terminal device, in order to improve the paging success rate, the network can directly send an Alert message to the first terminal device (i.e. without sending a paging message), and the first terminal device can prompt the user to perform the star alignment operation based on the Alert message and send a response message to the network after receiving the Alert message. Of course, when the first terminal device receives the Alert message, if the link quality meets certain conditions, such as the first terminal device has been star-aligned, the first terminal device does not need to perform the star alignment operation and can directly send a response message to the network.

[0206] For example, the network can first send a Paging message and wait for the response of the first terminal device, and then send an Alert message when the response of the first terminal device is not received. In this case, the first terminal device can prompt the user to perform the star alignment operation based on the Alert message after receiving the Alert message, and send a response message to the network after the user performs the star alignment operation. In addition, the Alert message can also be used to indicate that the network fails to page the first terminal device, i.e. the first terminal device can determine that the network fails to page the first terminal device before sending the Alert message to the first terminal device after receiving the Alert message.

[0207] For example, the network can also alternately send a Paging message and an Alert message for a preset number of times. The preset number of times can be set according to actual needs, and of course the number of times of sending the Paging message and the Alert message can also be different, which is not limited here.

[0208] For example, the strategy can also include whether to continue to perform Alert paging of the UE if no response of the first terminal device is received within a certain time. For example, the certain time is the Alert response time of the network to the first terminal device, and if the first terminal device sends an Alert response message within the Alert response time, the call can be connected. If the first terminal device does not send an Alert response message within the Alert response time, the call cannot be connected, and the network triggers a missed call reminder. In the case where it is determined that the call cannot be connected, the Alert strategy includes that the network continues to page the first terminal device so as to enable the first terminal device to obtain the missed call short message reminder as soon as possible. Under this strategy, it can be understood that the Alert sent within the certain time is used to enable the first terminal device to respond to the network after the call is connected, and the Alert message sent after the certain time is used to enable the first terminal device to obtain the missed call reminder short message after responding to the network.

[0209] Optionally, the first time length is different under different strategies if the first time length is related to the strategy of the case. For example, the first time length of performing paging paging first and then performing Alert paging is greater than the first time length of only performing Alert paging.

[0210] For example, in the case that the parameter information includes the strategy of the first mechanism / notification / capability, the first core network element determines the first time length according to the strategy of the first mechanism / notification / capability, which can specifically include that the first core network element can first acquire a second association relationship, which is used to represent the association relationship between the strategy of the first mechanism / notification / capability and the first time length.

[0211] For example, the paging strategy includes three paging strategies. For example, the paging strategy 1 is to perform only Alert paging when paging the first terminal device. The paging strategy 2 is to perform paging paging first and then perform Alert paging. The paging strategy 3 is to alternately send Paging paging and Alert paging for a preset number of times.

[0212] The second association relationship can be as shown in Table 2:

[0213] Table 2

[0214] Among them, the first time length corresponding to the paging strategy 1 is T3, the first time length corresponding to the paging strategy 2 is T4, the first time length corresponding to the paging strategy 3 is T4, and the first time length corresponding to the paging strategy 4 is T4.

[0215] It can be understood that the above-mentioned second association relationship can represent the association relationship between the paging strategy and the first time length after combining the paging strategy with the previous paging number, for example, the first time length corresponding to the paging strategy 1 and the Alert paging number a is T31. For example, the first time length corresponding to the paging strategy 1 and the Alert paging number b is T32. Wherein, a and b are positive integers greater than 0.

[0216] 3, the access network mode of the first terminal device.

[0217] Among them, the access network mode can be related to at least one of the following: satellite, communication system architecture (such as the 4G architecture shown in the foregoing FIG. 2A, the 5G architecture shown in FIG. 2B, or future communication system architecture, etc.), etc.

[0218] For convenience of description, the access network mode of the first terminal device is divided into satellite access network mode and non-satellite access network mode for example.

[0219] The satellite access network mode can be understood as the first terminal device accessing the network through a satellite. The non-satellite access network mode can be understood as the first terminal device not accessing the network through a satellite. The satellite access mode can be the transparent mode of FIG. 5A or the regeneration mode of FIG. 5B, and the like, which are not limited here.

[0220] It can be understood that in the case of a satellite access network mode, it can be further divided into a transparent mode or a regeneration mode, and the like.

[0221] Optionally, if the first time length is related to the parameter information of this case, the first time length is different under different access network modes. For example, the first time length of the first terminal device in the satellite access mode is different from the first time length in the non-satellite access mode. For example, the first time length in the satellite access mode is greater than the first time length in the non-satellite access mode.

[0222] For example, in the case where the parameter information includes the access network mode of the first terminal device, the first core network element determines the first time length according to the access network mode of the first terminal device, which can specifically include that the first core network element can first obtain a third association relationship, which is used to represent the association relationship between the access network mode of the first terminal device and the first time length. Or the third association relationship is used to represent the association relationship between the access network mode of the first terminal device and the first time length.

[0223] For example, the third association relationship can be as shown in Table 3:

[0224] Table 3

[0225] For example, the first time length of the first terminal device in the satellite access mode is T7, and the first time length of the first terminal device in the non-satellite access mode is T8. Optionally, T7 is greater than T8.

[0226] 4, the satellite access time of the first terminal device.

[0227] The satellite access time in the embodiment of the application has various interpretations, for example, the satellite access time refers to the time length from receiving the Alert message to successfully communicating with the satellite. Or it can be understood that the first terminal device needs a certain time (i.e. satellite access time) to successfully communicate with the satellite after receiving the alert message. For example, the satellite access time refers to the time length from the beginning of the satellite operation to the successful communication with the satellite.

[0228] The operation of pointing at the satellite can be understood as an operation of adjusting the direction, posture, etc. of the first terminal device to align with the satellite (the satellite providing service for the first terminal device) when communicating with the satellite. After performing the operation of pointing at the satellite, if the corresponding call has not been terminated, the first terminal device can establish a communication connection with the network and answer the call; if the corresponding call has been terminated, the first terminal device can establish a communication connection with the network and actively initiate a call.

[0229] In addition, there are various ways for the first core network element to determine the duration of pointing at the satellite. For example, the duration of pointing at the satellite of the first terminal device can be a statistical value (such as an average value, a maximum value, a minimum value, etc.) of multiple times of the operation of pointing at the satellite performed by the first terminal device within a period of time. For another example, the duration of pointing at the satellite of the first terminal device can be the duration of a certain operation of pointing at the satellite (such as the most recent operation of pointing at the satellite) performed by the first terminal device. For another example, the duration of pointing at the satellite of the first terminal device can be a statistical value (such as an average value, a maximum value, a minimum value, etc.) of multiple times of the operation of pointing at the satellite performed by multiple terminal devices within a period of time. For another example, the duration of pointing at the satellite of the first terminal device can be a statistical value (such as an average value, a maximum value, a minimum value, etc.) of the duration of a certain operation of pointing at the satellite (such as the most recent operation of pointing at the satellite) performed by multiple terminal devices, and the like.

[0230] For example, the duration of pointing at the satellite of the first terminal device can be t1, t2, or t3. For another example, the duration of pointing at the satellite of the first terminal device can be an average duration of t1, t2, and t3. For another example, the duration of pointing at the satellite of the first terminal device can be the maximum duration of t1, t2, and t3. For another example, the duration of pointing at the satellite of the first terminal device can be the minimum duration of t1, t2, and t3.

[0231] For example, the duration of pointing at the satellite of the first terminal device can be t4, t5, or t6. For another example, the duration of pointing at the satellite of the first terminal device can be the maximum duration of t4, t5, and t6. For another example, the duration of pointing at the satellite of the first terminal device can be the minimum duration of t4, t5, and t6. For another example, the duration of pointing at the satellite of the first terminal device can be an average duration of t4, t5, and t6.

[0232] Optionally, if the first time length is related to the parameter information of the case, i.e., the paging process needs to consider the time length of the first terminal device aiming at the satellite, the first terminal device needs to be left with the time length required for aiming at the satellite. In general, the first time length is at least greater than the time length of aiming at the satellite. Of course, according to actual needs, the first time length can also be set to be less than or equal to the time length of aiming at the satellite, etc., which is not limited here.

[0233] For example, different first time lengths correspond to different time lengths of aiming at the satellite.

[0234] For example, in the case where the parameter information includes the time length of the first terminal device aiming at the satellite, the first core network element determines the first time length according to the time length of the first terminal device aiming at the satellite, which can specifically include that the first core network element can first obtain a fourth association relationship, which is used to represent the association relationship between the time length of the first terminal device aiming at the satellite and the first time length. Or the fourth association relationship is used to represent the association relationship between the time length of the first terminal device aiming at the satellite and the first time length.

[0235] For example, taking the time length of aiming at the satellite as t1 or t2, the fourth association relationship can be as shown in Table 4:

[0236] Table 4

[0237] Wherein, the second time length corresponding to the time length t1 of aiming at the satellite is T9, and the second time length corresponding to the time length t2 of aiming at the satellite is T10.

[0238] It can be understood that the above two cases of the first information and the four cases of the parameter information are only examples, and in actual application, there can be other cases, for example, the above four cases can be used alone or in combination. For example, the first information is also used to indicate other information. For example, the parameter information can also include other information, etc., which is not limited here.

[0239] For example, the four cases are used in combination. For example, the first core network element determines the first time length based on whether the first terminal device activates the alert mechanism and the paging strategy. For example, the first core network element determines the first time length based on the paging strategy and the time length of aiming at the satellite. For example, the first core network element determines the first time length based on whether the alert mechanism is activated and the time length of aiming at the satellite. For example, the first core network element determines the first time length based on whether the first terminal device activates the alert mechanism, the paging strategy, and the time length of aiming at the satellite, etc., which is not limited here.

[0240] Step 602, the first core network element sends the first information to the first IMS network element.

[0241] The first core network element sends the first information to the first IMS network element. Correspondingly, the first IMS network element receives the first information sent by the first core network element.

[0242] Optionally, the UDM network element or the PCF network element sends the first information to the first IMS network element.

[0243] For example, the first IMS network element can send a Cx-Put / Cx-Pull message to the UDM network element. The UDM network element sends a Cx-Put response information (Resp) / Cx-Pull Resp to the first IMS network element. That is, the first information can be carried in the Cx-Put Resp / Cx-Pull Resp.

[0244] For example, the PCF network element sends the first information to the first IMS network element in a call establishment process. For example, the first IMS network element can send an authentication authorization request (AAR) to the PCF network element. The PCF network element sends an authentication authorization response (AAA) to the first IMS network element. That is, the first information can be carried in the AAA. The AAR can also be referred to as an authentication request or an authorization request, and the AAA can also be referred to as an authentication response or an authorization response.

[0245] In step 603, the first IMS network element determines the second time length based on the first information.

[0246] After the first IMS network element obtains the first information, the first IMS network element determines the second time length based on the first information. The second time length is used to control the operation related to the call of the first terminal device.

[0247] Optionally, the operation related to the call of the first terminal device can include terminating the call of the first terminal device, and / or re-sending a call request for calling the first terminal device.

[0248] For example, if the timer expires, the call of the first terminal device is terminated or the call request is re-sent. The role or function of the second time length will be described later in combination with an embodiment containing the timer, which will not be expanded here.

[0249] Similar to the above-mentioned various cases of the first information, this step is also divided into various cases.

[0250] In the first case, the first IMS network element determines the second time length based on the first time length.

[0251] In this case, after the first IMS network element receives the first time length sent by the first core network element, the first IMS network element can determine the second time length based on the first time length.

[0252] Optionally, the first IMS can increase the first time length by a preset time length to obtain the second time length. That is, the second time length is greater than the first time length. Alternatively, the first IMS takes the first time length as the second time length. That is, the second time length is equal to the first time length.

[0253] For example, the second time length can be a value within a range centered on the first time length. For example, the first time length is 20 seconds, and the second time length can take a value within the interval of 20-5 to 20+5.

[0254] In the second case, the first IMS network element determines the second time length based on the parameter information.

[0255] The first IMS network element determines the second time length based on the parameter information. Alternatively, it is understood that the second time length is related to the parameter information.

[0256] In this case, the first IMS network element determines the second time length based on the parameter information in a manner similar to the manner in which the first core network element determines the first time length based on the parameter information, that is, the association between the parameter information and the second time length can refer to the description of the association between the parameter information and the first time length, which will not be described here. For example, it can refer to the description of the first association relationship, the second association relationship, the third association relationship, the fourth association relationship, and the like in the aforementioned step 601, or it can be understood that the first time length in the aforementioned association relationships is replaced by the second time length to understand the process of determining the second time length based on the parameter information.

[0257] For example, the first IMS network element determines the second time length based on whether the first terminal device activates the first mechanism / notification / capability. For example, the first IMS network element determines the second time length based on the policy of the first mechanism / notification / capability. For example, the first IMS network element determines the second time length based on the access network mode of the first terminal device. For example, the first IMS network element determines the second time length based on the satellite time length of the first terminal device. For example, the first IMS network element determines the second time length based on whether the first terminal device activates the first mechanism / notification / capability and the access network mode. For example, the first IMS network element determines the second time length based on whether the first terminal device activates the first mechanism / notification / capability and the satellite time length. For example, the first IMS network element determines the second time length based on the paging policy and the access network mode. For example, the first IMS network element determines the second time length based on the paging policy and the satellite time length. For example, the first IMS network element determines the second time length based on the access network mode and the satellite time length.

[0258] It can be understood that the above-mentioned manner of determining the second time length by the first IMS network element based on the first information or the manner of determining the second time length based on the parameter information is only an example, and in actual application, there can be other cases, for example, the above-mentioned multiple cases of the parameter information can be used alone or in combination. For another example, the parameter information can further include other information, and the like, which is not limited here.

[0259] Optionally, the first core network element can further send a call request to the fourth core network element. The step of sending the call request can be before step 603 or after step 603, which will be described later in combination with the IMS registration process or the call establishment process, which is not expanded here.

[0260] In the embodiments of the present application, on the one hand, the first IMS network element controls the operation related to the call of the first terminal device through the second time length, and considers the enhanced paging mechanism / notification mechanism when determining the second time length, for example, the first time length required when calling the terminal device through the enhanced paging mechanism / notification mechanism or the parameter information related to the enhanced paging mechanism / notification mechanism needs to be considered when determining the second time length, which can reduce the problems such as the call being terminated incorrectly or the invalid waiting of the calling terminal due to the mismatch between the second time length and the enhanced paging mechanism / notification mechanism. On the other hand, different parameter information can correspond to different first time lengths or second time lengths. For example, the time length (such as the first time length or the second time length) of the satellite access network mode is greater than the time length (such as the first time length or the second time length) of the non-satellite access network mode, so as to reserve a certain time length for the user corresponding to the first terminal device to perform the satellite operation, so as to improve the normal communication between the first terminal device and the second terminal device.

[0261] The above-mentioned Fig. 6 describes the method provided by the embodiments of the present application in a framework, and the following will first describe the manner of obtaining the first information by the first IMS network element in combination with different scenarios or processes. For example, the first IMS network element can obtain the first information in the IMS registration process. For another example, the first IMS network element obtains the first information in the call establishment process.

[0262] Referring to FIG. 7, a flowchart of a communication method in an IMS registration scenario is provided, which can include steps 701-707. The steps 701-707 can be executed by a communication apparatus, or by some components (e.g., a processor, a chip or a chip system, etc.) in the communication apparatus, or by a logic module or software that can realize all or part of the functions of the communication apparatus. Hereinafter, the steps 701-707 are described by taking the execution by the communication apparatus as an example. The processes performed by a single execution subject in the steps 701-707 can also be divided into processes performed by multiple execution subjects, which can be logically and / or physically separated. For example, in the case of the communication apparatus being a core network device, the processes performed by the communication apparatus can be divided into processes performed by at least one of an AMF, an SMF, a UPF, a UDM, etc. For another example, in the case of the communication apparatus being an access network device, the processes performed by the communication apparatus can be divided into processes performed by at least one of a CU, a DU, a RU, etc. For yet another example, in the case of the communication apparatus being an IMS network element (e.g., a first IMS network element or a second IMS network element), the processes performed by the communication apparatus can be divided into processes performed by at least one of a P-CSCF, an S-CSCF, etc. The method can be applied to any one of the system architectures shown in FIGS. 1-5B, and the specific embodiments are not limited herein.

[0263] For the convenience of description, the core network device or each network element in the core network shown in FIG. 7 includes at least one of a first core network element, a second core network element, a third core network element, etc. The first core network element can be, for example, a UDM network element, a HSS network element, a PCF network element, a PCRF network element, etc. The second core network element can be, for example, an AMF network element or an MME, etc. The third core network element can be, for example, an SMF network element, etc. The steps 701-707 are described in detail as follows.

[0264] In step 701, a first terminal device establishes an IMS protocol data unit (PDU) session.

[0265] The first terminal device can send, to the third core network element, a PDU session establishment request message through the second core network element, the PDU session establishment request message including a data network name (DNN) being IMS, that is, the PDU session is used to carry IMS communication related signaling and data. In the process of performing the emergency call, the DNN included in the PDU session establishment request message can also be a DNN describing emergency communication, for example, emergency. After receiving the PDU session establishment request message, the third core network element sends, to the first terminal device, a PDU session establishment accept message, and the PDU session establishment accept message can include an IP address corresponding to the PDU session. The IP address is allocated by an SMF or a UPF for the first terminal device in the PDU session establishment process, and is used for subsequent communication of the first terminal device through the PDU session.

[0266] Optionally, the third core network element can establish a quality of service (QoS) flow for the first terminal device to carry IMS signaling, and a 5G QoS identifier (5QI) of the QoS flow is, for example, 5. More steps about establishing the PDU session are not described here.

[0267] In the PDU session establishment process, the first terminal device can also obtain an address of a P-CSCF in the IMS, which is used for subsequent communication of the first terminal device with the IMS.

[0268] In step 702, the first terminal device sends an IMS registration request to the first IMS network element.

[0269] The first terminal device can send a session initialization protocol (SIP) registration message to the first IMS network element (e.g., P-CSCF) through the IMS PDU session and the QoS flow established in step 701 to perform an IMS registration procedure or request to register to the IMS network. Optionally, the SIP registration message can include a private (P)-Access (A)-Network (N)-Info information element, which can indicate that the first terminal device accesses the network through a satellite. For example, the first terminal device can receive system information from an access network element, and determine whether the first terminal device accesses the network through a satellite according to the system information. Alternatively, the first terminal device can also determine whether the first terminal device accesses the network through a satellite according to the PLMN in which the first terminal device is located.

[0270] Optionally, the first terminal device sends an IMS registration request to the first IMS network element, specifically, the first terminal device sends an IMS registration request to the P-CSCF, and the P-CSCF sends the registration request to the S-CSCF.

[0271] In step 703, the first IMS network element sends a Cx-Put message / Cx-Pull message to the first core network element.

[0272] The first IMS network element sends a Cx-Put message / Cx-Pull message to the first core network element. Correspondingly, the first core network element receives the Cx-Put message / Cx-Pull message sent by the IMS network element.

[0273] The Cx-Put message / Cx-Pull message can include or indicate at least one of the following: whether the first terminal device activates the first mechanism / indication / capability, the policy of the first mechanism / indication / capability, the access network mode of the first terminal device, the satellite access time of the first terminal device, etc.

[0274] Optionally, after receiving the registration request, the S-CSCF sends a Cx-Put message / Cx-Pull message to the first core network element.

[0275] For example, the Cx-Put message / Cx-Pull message is used to request the subscription information of the first terminal device.

[0276] In step 704, the first core network element determines the first information.

[0277] After the first core network element receives the Cx-Put message / Cx-Pull message sent by the IMS network element, the first information is determined. The first information can refer to the description in the foregoing embodiment shown in FIG. 6, and will not be described here again.

[0278] Optionally, after the first core network element receives the Cx-Put message / Cx-Pull message sent by the IMS network element, the subscription information of the first terminal device is determined. The subscription information can include part or all of the first information in the foregoing embodiment shown in FIG. 6. For example, the subscription information includes at least one of the following: whether the first terminal device activates the first mechanism / indication / capability, the policy of the first mechanism / indication / capability, and the like.

[0279] In step 705, the first core network element sends a Cx-Put Resp message / Cx-Pull Resp message to the first IMS network element.

[0280] After the first core network element determines the first information, the first core network element sends a Cx-Put Resp message / Cx-Pull Resp message to the first IMS network element. Correspondingly, the first IMS network element receives the Cx-Put Resp message / Cx-Pull Resp message sent by the first core network element. The Cx-Put Resp message / Cx-Pull Resp message carries or indicates the subscription information or the first information described above.

[0281] In step 706, the first IMS network element sends a 200 OK to the first terminal device.

[0282] After step 702, if the registration is successful, the first IMS network element sends a SIP registration ok (or 200 OK) message to the first terminal device.

[0283] In step 707, the first IMS network element determines a second time length based on the first information.

[0284] After the first IMS network element receives the Cx-Put Resp message / Cx-Pull Resp message, the second time length is determined based on the first information.

[0285] In this step 707, the foregoing step 603 in the embodiment shown in FIG. 6 can be referred to, and will not be described here again.

[0286] Based on the above scheme, the first IMS network element can obtain the first information in the IMS registration scenario, and determine the second time length through the second information. The first IMS network element controls the operation related to the call of the first terminal device through the second time length, and determines the second time length considering the enhanced paging mechanism / notification mechanism, etc., for example, when determining the second time length, the first time length required when calling the terminal device through the enhanced paging mechanism / notification mechanism or the parameter information related to the enhanced paging mechanism / notification mechanism needs to be considered, which can reduce the problems such as the call being terminated by mistake or the invalid waiting of the calling terminal due to the mismatch between the second time length and the enhanced paging mechanism / notification mechanism. On the other hand, different parameter information can correspond to different first time lengths or second time lengths. For example, the time length (such as the first time length or the second time length) of the satellite access network mode is greater than the time length (such as the first time length or the second time length) of the non-satellite access network mode, so as to reserve a certain time length for the user corresponding to the first terminal device to perform the satellite operation, so as to improve the normal communication between the first terminal device and the second terminal device.

[0287] Please refer to FIG. 8, the flowchart of the communication method in the call establishment scenario provided by the embodiment of the present application, which can include steps 801 to 806. Steps 801 to 806 can be executed by the communication device, or can be executed by part of the components (such as the processor, chip or chip system, etc.) in the communication device, or can be realized by the logic module or software which can realize all or part of the functions of the communication device. The following is described by taking the execution of the communication device as an example. The processing executed by a single execution subject in steps 801 to 806 can also be divided into the execution of multiple execution subjects, which can be logically and / or physically separated. For example, in the case of the communication device being a core network device, the processing executed by the communication device can be divided into the execution of at least one of the AMF, SMF, UPF, PCF, etc. For another example, in the case of the communication device being an access network device, the processing executed by the communication device can be divided into the execution of at least one of the CU, DU and RU, etc. For another example, in the case of the communication device being an IMS network element (such as the first IMS network element or the second IMS network element), the processing executed by the communication device can be divided into the execution of at least one of the P-CSCF, S-CSCF, etc. The method can be applied to any one of the system architectures shown in FIGS. 1 to 5B, and the specific embodiments are not limited here.

[0288] For the convenience of description, the core network device or each network element in the core network shown in FIG. 8 includes at least one of the following: the first core network network element (such as the UDM network element, the HSS network element, the PCF network element, the PCRF network element), etc. The steps 801 to 806 are described in detail as follows.

[0289] Step 801, the second terminal device sends a call request 1 to a second IMS network element.

[0290] The second terminal device sends a call request 1 (or called call request message 1) to the second IMS network element. Correspondingly, the second IMS network element receives the call request 1 sent by the second terminal device. The call request is a request of the second terminal device to call the first terminal device.

[0291] The call request 1 is a message of the second terminal device to request to call the first terminal device. The call request 1 includes a calling number (such as a calling telephone (TEL) uniform resource locator (URL)) and a called number. The calling number is a number corresponding to the calling party (i.e. the second terminal device), which corresponds to the content of the from field in the message header of the call request 1. The called number is a number corresponding to the called party (i.e. the first terminal device), which corresponds to the content of the to field in the message header of the call request 1. It can be understood that the above-mentioned call request 1 is triggered by the second terminal device.

[0292] Optionally, the second IMS network element can be a P-CSCF or an S-CSCF. For example, the P-CSCF receives the call request 1 from the second terminal device. For another example, the P-CSCF first receives the call request 1 from the second terminal device. Then, the P-CSCF sends the call request 1 to the S-CSCF after a certain processing (such as adding, deleting or modifying part or all information in the message header) of the P-CSCF.

[0293] Step 802, the second IMS network element sends a call request 2 to a first IMS network element.

[0294] After the second IMS network element receives the call request 1 sent by the second terminal device, the second IMS network element sends a call request 2 to the first IMS network element. Correspondingly, the first IMS network element receives the call request 2 sent by the second IMS network element.

[0295] It should be noted that the SIP message transmitted between the two terminal devices can be processed by each IMS network element before being transmitted to the next network element. For example, the call request of the second terminal device is transmitted from the second terminal device to the first terminal device, and needs to pass through the P-CSCF of the second terminal device (i.e., the P-CSCF in the IMS network where the second IMS network element is located), the S-CSCF of the second terminal device (i.e., the S-CSCF in the IMS network where the second IMS network element is located) to the S-CSCF of the first terminal device (i.e., the S-CSCF in the IMS network where the first IMS network element is located), the P-CSCF of the first terminal device (i.e., the P-CSCF in the IMS network where the first IMS network element is located), and finally sent to the first terminal device by the P-CSCF of the first terminal device. Therefore, the call request can be processed (e.g., part or all information in the message header is added, deleted, or modified) by the P-CSCF of the second terminal device, the S-CSCF of the second terminal device, the S-CSCF of the first terminal device, and the P-CSCF of the first terminal device, and this description applies to all subsequent SIP messages in the embodiments.

[0296] Alternatively, it is understood that the call request 2 is obtained by processing (e.g., adding, deleting, or modifying part or all information in the message header) the call request 1.

[0297] Alternatively, it is understood that there can be slight differences between the call requests of different network elements in the embodiments of the present application, such as header addition, deletion, or modification.

[0298] Step 803, the first IMS network element sends an authentication and authorization request (AA-Request, AAR) to the first core network element.

[0299] After receiving the call request 2, the first IMS network element sends an AAR to the first core network element. Correspondingly, the first core network element receives the AAR sent by the first IMS network element.

[0300] The AAR can include or indicate at least one of the following: the first time length, whether the first terminal device activates the first mechanism / notification / capability, the policy of the first mechanism / notification / capability, the access network mode of the first terminal device, the star time length of the first terminal device, etc.

[0301] Step 804, the first core network element determines the first information.

[0302] After receiving the AAR sent by the first IMS network element, the first core network element determines the first information. The first information can refer to the description in the embodiment shown in FIG. 6 described above, which will not be described here.

[0303] Optionally, after receiving the AAR sent by the first IMS network element, the first core network element determines at least one of the following based on the AAR: the first time length, whether the first terminal device activates the first mechanism / notification / capability, a policy of the first mechanism / notification / capability, an access network mode of the first terminal device, a satellite access time length of the first terminal device, and the like.

[0304] At step 805, the first core network element sends an authentication and authorization response (AA-Answer, AAA) to the first IMS network element.

[0305] After receiving the AAR sent by the first IMS network element, the first core network element sends the AAA to the first IMS network element. Correspondingly, the first IMS network element receives the AAA sent by the first core network element.

[0306] It can be understood that the AAA in step 806 can also be replaced by a re-authentication authorization response (RAA) or the like, which is not limited here.

[0307] At step 806, the first IMS network element determines a second time length based on the first information.

[0308] After receiving the AAA, the first IMS network element determines the second time length based on the first information.

[0309] In this step 806, reference can be made to the description of step 603 in the foregoing embodiment shown in FIG. 6, which will not be repeated here.

[0310] Based on the above scheme, the first IMS network element can obtain the first information in an IMS registration scenario, and determine the second time length through the second information. The first IMS network element controls the operation related to the call of the first terminal device through the second time length, and determines the second time length considering the enhanced paging mechanism / notification mechanism, for example, needs to consider the first time length required when calling the terminal device through the enhanced paging mechanism / notification mechanism or the parameter information related to the enhanced paging mechanism / notification mechanism when determining the second time length, which can reduce the problems such as the call being terminated incorrectly or the invalid waiting of the calling terminal due to the mismatch between the second time length and the enhanced paging mechanism / notification mechanism. On the other hand, different parameter information can correspond to different first time lengths or second time lengths. For example, the time length (such as the first time length or the second time length) of the satellite access network mode is greater than the time length (such as the first time length or the second time length) of the non-satellite access network mode, so as to reserve a certain time length for the user corresponding to the first terminal device to perform the satellite access operation, so as to improve the normal communication between the first terminal device and the second terminal device.

[0311] The above FIG. 7 and FIG. 8 respectively introduce different manners of the first IMS network element obtaining the first information in different scenarios, and the following describes the part that can be shared by FIG. 6 to FIG. 8 in combination with FIG. 9. For example, the steps shown in FIG. 9 can be combined with the embodiment shown in FIG. 6. For another example, the steps shown in FIG. 9 can be combined with the embodiment shown in FIG. 7. For another example, the steps shown in FIG. 9 can be combined with the embodiment shown in FIG. 8.

[0312] Please refer to FIG. 9, the flow diagram of another communication method provided by the embodiment of the present application, which can include steps 901 to 907. Steps 901 to 907 can be executed by a communication device, or can be executed by part components (such as processor, chip or chip system, etc.) in the communication device, or can be implemented by a logic module or software that can realize all or part of the function of the communication device. The following is described by taking the execution of the communication device as an example. The processing executed by a single execution subject in steps 901 to 907 can also be divided into the execution of multiple execution subjects, which can be logically and / or physically separated. For example, in the case of the communication device being a core network equipment, the processing executed by the communication device can be divided into the execution of at least one of the network elements such as AMF, SMF, UPF, UDM, PCF, etc. For another example, in the case of the communication device being an access network equipment, the processing executed by the communication device can be divided into the execution of at least one of the network elements such as CU, DU and RU, etc. For another example, in the case of the communication device being an IMS network element (such as the first IMS network element or the second IMS network element), the processing executed by the communication device can be divided into the execution of at least one of the network elements / entities such as P-CSCF, S-CSCF, etc. The method can be applied to any one of the system architectures shown in FIG. 1 to FIG. 5B, and the specific embodiments are not limited here.

[0313] For the convenience of description, the core network equipment or each network element in the core network shown in FIG. 9 includes at least one of the following: the first core network network element, the second core network network element, the third core network network element, the fourth core network network element, etc. The first core network network element can be, for example, a UDM network element, a HSS network element, a PCF network element, a PCRF network element, etc. The second core network network element can be, for example, an AMF network element or an MME, etc. The third core network network element can be, for example, an SMF network element, etc. The fourth core network network element can be, for example, a UPF network element, etc. The following describes steps 901 to 907 in detail.

[0314] In step 901, the second terminal device sends a call request 1 to the second IMS network element.

[0315] In step 902, the second IMS network element sends a call request 2 to the first IMS network element.

[0316] In the embodiment, steps 901 and 902 can refer to the description of steps 801 and 802 in the embodiment of FIG. 8, which will not be repeated here.

[0317] In step 903, the first IMS network element determines the second time length based on the first information.

[0318] After receiving the call request 2, the first IMS network element determines the second time length based on the first information.

[0319] In the embodiment, step 903 can refer to the description of step 603 in the embodiment of FIG. 6, which will not be repeated here.

[0320] In step 904, the first IMS network element sends the second time length to the second IMS network element.

[0321] After determining the second time length, the first IMS network element sends the second time length to the second IMS network element. Correspondingly, the second IMS network element receives the second time length sent by the first IMS network element. The description of the second time length can refer to the description of step 603 in the embodiment of FIG. 6, which will not be repeated here.

[0322] In step 905, the second IMS network element sends prompt information to the second terminal device. This step is optional.

[0323] Optionally, after receiving the second time length sent by the first IMS network element, the second IMS network element sends prompt information to the second terminal device. The prompt information is used to prompt the second terminal device to wait for call connection.

[0324] The prompt information in the embodiment can be presented in the form of an image, text, or sound. For example, the second IMS network element can play a prompt sound “the called terminal device may need a long time, please do not hang up, and wait patiently for the prompt” through the second terminal device.

[0325] Optionally, the prompt information is also used to prompt the waiting time length of the second terminal device. The waiting time length is related to the second time length. For example, the waiting time length is equal to the second time length, and for example, the waiting time length is greater than or less than the second time length, and the like, which will not be limited here. Generally, in order to ensure the call connection of the second terminal device, the waiting time length is usually greater than the second time length.

[0326] Based on the above manner, the second IMS network element sends prompt information to the second terminal device, so that the second terminal device will not hang up during the waiting for call connection, preventing the second terminal device from not receiving the reply of the first terminal device.

[0327] In step 906, the first IMS network element sends a call request 3 to the fourth core network element.

[0328] After the first IMS network element receives the call request 2 sent by the second IMS network element, it sends a call request 3 to the fourth core network network element. Correspondingly, the fourth core network network element receives the call request 3 sent by the first IMS network element.

[0329] The call request 3 can refer to the description of the call request between different network elements in step 802 of the embodiment shown in FIG. 8. For example, the call request 3 is obtained by processing (e.g., adding, deleting, or modifying part or all of the information in the message header) the call request 2.

[0330] Optionally, the call request 3 is also used by the second core network network element to page the first terminal device.

[0331] For example, the first IMS network element sends the call request 3 to the fourth core network network element in the core network device, which can be sent in the form of an IP packet. After receiving the IP packet, the fourth core network network element issues a data notification to the third core network network element. Specifically, when the fourth core network network element determines that the IMS PDU session of the first terminal device has no corresponding base station side tunnel information (AN Tunnel info), it sends a downlink data (DL data) notification message to the third core network network element, which includes an N4 session identifier associated with the IMS PDU session of the first terminal device. The third core network network element can invoke the service provided by the second core network network element to send an N1N2 message to the second core network network element, where the N1 message is a message sent by the third core network network element to the first terminal device through the second core network network element, the N2 message is a message sent by the third core network network element to the access network device (e.g., base station) through the second core network network element, and the N1N2 message is used to establish or activate the PDU session / QoS flow for the first terminal device and the access network device, respectively.

[0332] In step 907, the first IMS network element sets or starts a timer based on the second time length.

[0333] After the first IMS network element sends the call request 3 to the fourth core network network element, it can set / start a timer based on the second time length. If the timer expires, the call to the first terminal device is terminated or the call request is resent. If the timer does not expire, the response of the first terminal device is waited.

[0334] Alternatively, it is understood that the timer is used to determine whether to terminate the call to the first terminal device or to determine whether to resend the call request 3.

[0335] Optionally, if the second time length is determined according to whether the first terminal device subscribes to the warning mechanism, the first IMS network element can use different timers for whether the first terminal device subscribes to the warning mechanism.

[0336] The timing between the steps in the embodiment can not be strictly according to the timing shown in FIG. 6, that is, there can be no timing relationship between some steps in the embodiment. For example, step 906 can be before or after step 903. For another example, step 906 can be before or after step 904. For another example, step 905 can be before or after step 906. For another example, step 905 can be before or after step 907, and so on. The timing between the steps in the embodiment is not limited.

[0337] In the embodiment of the application, on the one hand, the first IMS network element controls the operation related to the call of the first terminal device through the second time length, and determines the second time length considering the enhanced paging mechanism / notification mechanism, for example, the first time length required when calling the terminal device through the enhanced paging mechanism / notification mechanism or the parameter information related to the enhanced paging mechanism / notification mechanism needs to be considered when determining the second time length, which can reduce the problems such as the call being terminated incorrectly or the invalid waiting of the calling terminal due to the mismatch between the second time length and the enhanced paging mechanism / notification mechanism. On the other hand, different parameter information can correspond to different first time lengths or second time lengths. For example, the time length (such as the first time length or the second time length) of the satellite access network mode is greater than the time length (such as the first time length or the second time length) of the non-satellite access network mode, so as to reserve a certain time length for the user corresponding to the first terminal device to perform the satellite operation, so as to improve the subsequent normal communication between the first terminal device and the second terminal device. On the other hand, the second IMS network element can prompt the second terminal device to wait for the call to be connected by sending prompt information to the second terminal device, so that the second terminal device can patiently wait for the reply of the first terminal device, and reduce the communication abnormality caused by the premature estimation of the second terminal device.

[0338] In order to more directly show the specific interaction of each network element in the core network or the core network device in any of the above embodiments shown in FIGS. 6 to 9, the embodiment shown in FIG. 7 is further described by FIG. 10, and the embodiment shown in FIG. 8 is further described by FIG. 11.

[0339] Please refer to FIG. 10, a flowchart of another communication method provided by the embodiments of the present disclosure is shown, which can include steps 1001 to 1017. The steps 1001 to 1017 can be executed by a communication device, or by some components (such as a processor, a chip or a chip system, etc.) in the communication device, or by a logic module or software that can realize all or part of the functions of the communication device. Hereinafter, the steps 1001 to 1017 are described by taking the execution by the communication device as an example. The processes executed by a single execution subject in the steps 1001 to 1017 can also be divided into processes executed by multiple execution subjects, which can be logically and / or physically separated. For example, in the case where the communication device is a core network device, the processes executed by the communication device can be divided into processes executed by at least one of the network elements such as an AMF, an SMF, a UPF, and a UDM. For another example, in the case where the communication device is an access network device, the processes executed by the communication device can be divided into processes executed by at least one of the network elements such as a CU, a DU, and a RU. The method can be applied to any one of the embodiments shown in FIGS. 1 to 7 or 9, and the specific embodiments are not limited herein.

[0340] For the convenience of description, the core network device or each network element in the core network shown in FIG. 10 includes at least one of the following: a first core network element, a second core network element, a third core network element, and a fourth core network element, etc. The first core network element can be, for example, a UDM network element, a HSS network element, a PCF network element, a PCRF network element, etc. The second core network element can be, for example, an AMF network element or an MME, etc. The third core network element can be, for example, an SMF network element, etc. The fourth core network element can be, for example, a UPF network element, etc. The first terminal device is referred to as a called terminal device, the second terminal device is referred to as a calling terminal device, the first IMS network element is referred to as an IMS network element serving the called UE, and the second IMS network element is referred to as an IMS network element serving the caller. The steps 1001 to 1017 are described in detail as follows.

[0341] In step 1001, the called terminal device sends a registration request information (registration request) to the AMF network element.

[0342] In a process of registering a network, the called terminal device sends a registration request information to an AMF network element. Correspondingly, the AMF network element receives the registration request information sent by the called terminal device. The registration request information includes or is used to indicate the capability information of the called terminal device. The capability information is used to indicate whether the called terminal device has the capability of receiving an Alert message, or is used to indicate whether the called terminal device supports paging enhancement, or is used to indicate whether the called terminal device supports flexible notification, etc. After receiving the registration request information, the AMF network element can determine whether to activate the alert mechanism according to a policy. The policy includes at least one of the following: the Alert capability information reported by the called terminal device, whether the called terminal device subscribes to the Alert service function of the network, whether there is an access network device (such as a base station) supporting the Alert capability in the registration area of the called terminal device, and the load condition of the network performing paging, etc.

[0343] In step 1002, the AMF network element sends an Alert activation indication (Nudm UECM registration) to a UDM network element. This step is optional.

[0344] Optionally, the AMF network element can determine whether the called terminal device activates the alert mechanism according to the capability information reported by the called terminal device. When the capability information reported by the called terminal device supports the alert capability, it is determined to activate the alert mechanism and send the Alert activation indication to the UDM network element. When the capability information reported by the called terminal device does not support the alert capability, it is determined not to activate the alert mechanism. In addition, the AMF determines whether to activate the alert mechanism for the called terminal, which can also be combined with other information, such as whether the terminal device subscribes to the alert service.

[0345] Further, the UDM network element can save the content indicated by the Alert activation indication. For example, the UDM network element can save the maximum time length of paging the called terminal device.

[0346] Of course, if the registration request in the foregoing step 1001 does not include the alert capability information of the called terminal device, it can be understood that the terminal device does not support the alert capability, and the AMF does not activate the alert mechanism for the terminal device. In addition, whether the AMF activates the alert mechanism for the terminal device can not depend on the alert capability of the terminal, and the AMF network element can obtain the subscription information of the previous called terminal device from the UDM network element. If the subscription information includes the Alert subscription information, it is determined that the called terminal device activates the alert mechanism. Alternatively, the AMF network element can also determine the first time length for paging the called terminal device, in which case the AMF network element can also send the first time length for paging the called terminal device to the UDM network element. The first time length can be related to the parameter information in the foregoing embodiment shown in FIG. 6, and is not limited here.

[0347] Step 1003: The AMF network element sends a registration acceptance information (registration accept) to the called terminal device.

[0348] After the AMF network element receives the registration request sent by the called terminal device, the AMF network element sends a registration accept to the called terminal device. Correspondingly, the called terminal device receives the registration accept sent by the AMF network element. The registration accept includes an Alert activation indication, which is used to indicate that the AMF network element will page the called terminal device by sending an Alert message to the called terminal device. Correspondingly, the terminal device starts to monitor / detect the alert message when it is determined that certain conditions are met based on the Alert activation indication.

[0349] Step 1004: The called terminal device establishes an IMS PDU session.

[0350] The called terminal device can send a PDU session establishment request message to the SMF network element through the AMF network element. The PDU session establishment request message includes a data network name (DNN) of IMS. The PDU session is used to carry IMS channel related signaling and data. After receiving the PDU session establishment request, the SMF network element sends a PDU session establishment accept message to the called terminal device. Correspondingly, the called terminal device receives the PDU session establishment accept message sent by the SMF network element. In addition, during the IMS PDU session establishment process, the called terminal device can also obtain the address of the P-CSCF in the IMS network, for subsequent communication with the IMS network.

[0351] Optionally, step 1004 of this embodiment can refer to the description in step 701 of the foregoing embodiment shown in FIG. 7, which will not be described here again.

[0352] Step 1005: The called terminal device sends IMS / SIP registration information (IMS / SIP registration) to the called IMS network element.

[0353] The called terminal device can send a SIP registration to the called IMS network element (for example, P-CSCF) through the established IMS PDU session, to perform an IMS registration process, or request to register to the called IMS network element.

[0354] Optionally, step 1005 of this embodiment can refer to the description in step 702 of the foregoing embodiment shown in FIG. 7, which will not be described here again.

[0355] Step 1006: The called IMS network element sends a Cx-Put / Cx-Pull to the UDM network element.

[0356] The called IMS network element can send a Cx-Put / Cx-Pull message to the UDM network element. Correspondingly, the UDM network element receives the Cx-Put / Cx-Pull message sent by the called IMS network element.

[0357] Optionally, step 1006 of this embodiment can refer to the description in step 703 of the foregoing embodiment shown in FIG. 7, which will not be described here again.

[0358] Step 1007: The UDM network element sends a Cx-Put response information (Resp) / Cx-Pull Resp to the called IMS network element.

[0359] The UDM network element sends a Cx-Put Resp / Cx-Pull Resp to the called IMS network element. Correspondingly, the called IMS network element receives the Cx-Put Resp / Cx-Pull Resp sent by the UDM network element.

[0360] Optionally, the first time length for paging the called terminal device or the parameter information in the foregoing embodiment shown in FIG. 6 is carried in the Cx-Put Resp / Cx-Pull Resp. Alternatively, the Cx-Put Resp / Cx-Pull Resp is used to indicate the first time length or the parameter information.

[0361] Optionally, step 1007 in this embodiment can refer to the description in step 705 in the foregoing embodiment shown in FIG. 7, which is not described here again.

[0362] Step 1008: The called IMS network element sends an IMS registration OK (or 200 OK) to the called terminal device.

[0363] If the called terminal device succeeds in registering in the IMS network, the called terminal device can receive a SIP registration ok (or 200 OK) message from the called IMS network element (for example, a P-CSCF). Through the foregoing process, the called terminal device registers in the IMS network, and can subsequently perform relevant call services through the IMS network. It can be understood that the process of registering the IMS by the called terminal device is similar to the process of registering the IMS by the called terminal device, which is not described here again.

[0364] Optionally, step 1008 in this embodiment can refer to the description in step 706 in the foregoing embodiment shown in FIG. 7, which is not described here again.

[0365] Step 1009: The called terminal device sends a SIP invite to the called IMS network element. The SIP invite in this step can refer to the call request 1 in the foregoing embodiment.

[0366] Step 1010: The called IMS network element sends a SIP invite to the called IMS network element. The SIP invite in this step can refer to the call request 2 in the foregoing embodiment.

[0367] Step 1011: The called IMS network element sends the first time length or the second time length for paging the called terminal device to the called IMS network element. This step can refer to step 904 in the foregoing embodiment shown in FIG. 9.

[0368] Step 1012: The called IMS network element determines an invite response message timer based on the second time length.

[0369] The second time length is obtained based on the first time length or the parameter information. This step can refer to step 907 in the embodiment shown in FIG. 9.

[0370] In step 1013, the calling IMS network element sends prompt information to the calling terminal device. This step is optional. This step can refer to step 905 in the embodiment shown in FIG. 9.

[0371] In step 1014, the called IMS network element sends a SIP invite to the UPF network element. This step can refer to the call request 3 in the foregoing embodiment.

[0372] In step 1015, the UPF network element sends a DL data notification to the SMF network element.

[0373] In step 1016, the SMF network element sends an N1N2 message transmission to the AMF network element.

[0374] In step 1017, the AMF network element pages the called terminal device through an access network device.

[0375] In steps 1014 to 1017, the called IMS network element sends a call request 3 to the UPF network element, which can be in the form of an IP packet. After receiving the IP packet, the UPF network element sends a data notification to the SMF network element. Specifically, when the UPF network element determines that the IMS PDU session of the second terminal device does not have corresponding base station side tunnel information (AN Tunnel info), it sends a downlink data (DL data) notification message to the SMF network element, which includes an N4 session identifier associated with the IMS PDU session of the second terminal device. The SMF network element can invoke a service provided by the AMF network element to send an N1N2 message to the AMF network element, where the N1 message is a message sent by the SMF network element to the first terminal device through the AMF network element, the N2 message is a message sent by the SMF network element to the access network device (such as a base station) through the AMF network element, and the N1N2 message is used to establish or activate a PDU session / QoS flow for the first terminal device and the access network device. If the AMF network element determines that the first terminal device is in an idle state, it sends a paging message and / or an Alert message to the access network device to page the first terminal device. Specifically, the first terminal device can be paged according to the paging strategy described above.

[0376] It can be seen that, on the one hand, the called IMS network element receives the Cx-Put Resp / Cx-Pull Resp sent by the UDM network element, and since the Cx-Put Resp / Cx-Pull Resp is used to indicate the first information, the first information can be obtained in the IMS registration process, so that the second time length can be determined according to the first information. On the other hand, the called IMS network element controls the operation related to the call of the called terminal device through the second time length, and determines the second time length considering the enhanced paging mechanism / notification mechanism and the like, for example, when determining the second time length, the first time length required when calling the terminal device through the enhanced paging mechanism / notification mechanism or the parameter information related to the enhanced paging mechanism / notification mechanism needs to be considered, which can reduce the problems such as the call being terminated by mistake or the invalid waiting of the calling terminal due to the mismatch between the second time length and the enhanced paging mechanism / notification mechanism. On the other hand, different parameter information can correspond to different first time lengths or second time lengths. For example, the time length (such as the first time length or the second time length) of the satellite access network mode is greater than the time length (such as the first time length or the second time length) of the non-satellite access network mode, so as to reserve a certain time length for the satellite operation of the user corresponding to the called terminal device, so as to improve the normal communication between the calling terminal device and the called terminal device.

[0377] Referring to FIG. 11, a flowchart of another communication method provided by an embodiment of the present application is shown, which can include steps 1101 to 1117. The steps 1101 to 1117 can be executed by a communication apparatus, or by some components (such as a processor, a chip or a chip system, etc.) in the communication apparatus, or by a logic module or software capable of realizing all or part of the functions of the communication apparatus. Hereinafter, the steps 1101 to 1117 are described by taking the execution by the communication apparatus as an example. The processes executed by a single execution subject in the steps 1101 to 1117 can also be divided into processes executed by multiple execution subjects, which can be logically and / or physically separated. For example, in the case where the communication apparatus is a core network device, the processes executed by the communication apparatus can be divided into processes executed by at least one of the network elements such as an AMF, an SMF, a UPF and a PCF. For another example, in the case where the communication apparatus is an access network device, the processes executed by the communication apparatus can be divided into processes executed by at least one of the network elements such as a CU, a DU and a RU. The method can be applied to any one of the embodiments shown in FIGS. 1 to 6, 8 or 9, and the specific embodiments are not limited herein.

[0378] For convenience of description, the core network device or each network element in the core network shown in FIG. 11 includes at least one of the following: a first core network element, a second core network element, a third core network element, and a fourth core network element, etc. The first core network element can be, for example, a UDM network element, a HSS network element, a PCF network element, a PCRF network element, etc. The second core network element can be, for example, an AMF network element or an MME, etc. The third core network element can be, for example, an SMF network element, etc. The fourth core network element can be, for example, a UPF network element, etc. The first terminal device is referred to as a called terminal device, the second terminal device is referred to as a calling terminal device, the first IMS network element is referred to as a called IMS network element, and the second IMS network element is referred to as a calling IMS network element. The steps 1101 to 1117 are described in detail below.

[0379] In step 1101, the called terminal device sends registration request information to the AMF network element.

[0380] In the process of registering the network, the called terminal device sends the registration request information to the AMF network element. Correspondingly, the AMF network element receives the registration request information sent by the called terminal device. The registration request information includes or is used to indicate the capability information of the called terminal device. The capability information is used to indicate whether the called terminal device has the capability to receive the Alert message, or is used to indicate whether the called terminal device supports paging enhancement, or is used to indicate whether the called terminal device supports flexible notification, etc. After receiving the registration request information, the AMF network element can determine whether to activate the alert mechanism according to the policy. The policy includes at least one of the following: the Alert capability information reported by the called terminal device, whether the called terminal device subscribes to the Alert service function in the network, whether there is an access network device (such as a base station) supporting the Alert capability in the registration area of the called terminal device, and the load condition of the network performing paging, etc.

[0381] In step 1102, the AMF network element sends an AM Policy Association establishment or an AM Policy Association modification to the PCF network element. This step is optional.

[0382] Optionally, the AMF network element can determine whether the called terminal device activates the alert mechanism according to the capability information reported by the called terminal device. And sends the AM Policy Association establishment / modification to the PCF network element.

[0383] Further, the PCF network element can save the content indicated by the Alert activation indication. For example, the PCF network element can save the maximum time length of paging the called terminal device.

[0384] Of course, if the registration request in the foregoing step 1101 does not include the capability information of the called terminal device, the step 1102 can not be performed. In this case, the AMF network element can obtain the subscription information of the called terminal device from the PCF network element. If the subscription information includes the Alert subscription information, it is determined that the called terminal device activates the alert mechanism.

[0385] Optionally, the AMF network element can also determine the first time length of paging the called terminal device, and in this case, the AMF network element can also send the first time length of paging the called terminal device to the PCF network element. The first time length can be related to the parameter information in the foregoing embodiment shown in FIG. 6, and the specific implementation is not limited here.

[0386] In step 1103, the AMF network element sends a registration accept to the called terminal device.

[0387] After the AMF network element receives the registration request sent by the called terminal device, the AMF network element sends a registration accept to the called terminal device, and correspondingly, the called terminal device receives the registration accept sent by the AMF network element. The registration accept includes an Alert activation indication, which is used to indicate that the AMF network element will page the called terminal device by sending an Alert message to the called terminal device.

[0388] In step 1104, the called terminal device establishes an IMS PDU session.

[0389] The called terminal device can send a PDU session establishment request message to the SMF network element through the AMF network element. The PDU session establishment request message includes a data network name (DNN) of IMS. The PDU session is used to carry IMS channel related signaling and data. After receiving the PDU session establishment request, the SMF network element sends a PDU session establishment accept message to the called terminal device. Correspondingly, the called terminal device receives the PDU session establishment accept message sent by the SMF network element. In addition, during the IMS PDU session establishment process, the called terminal device can also obtain the address of the P-CSCF in the IMS network, for subsequent communication of the called terminal device with the IMS.

[0390] Step 1105, the called terminal device sends IMS / SIP registration information (IMS / SIP registration) to the called IMS network element.

[0391] The called terminal device can send a SIP registration to the called IMS network element (for example, P-CSCF) through the established IMS PDU session, to perform an IMS registration process or request to register to the called IMS network element.

[0392] Step 1106, the called IMS network element sends an IMS registration OK (or 200OK) to the called terminal device.

[0393] If the called terminal device is successfully registered in the IMS network, the called terminal device can receive a SIP registration ok (or 200OK) message from the called IMS network element (for example, P-CSCF). Through the above process, the called terminal device is registered in the IMS network, and can subsequently perform related call services through the IMS network. It can be understood that the process of the calling terminal device registering the IMS is similar to the process of the called terminal device registering the IMS, and will not be described here.

[0394] Step 1107, the calling terminal device sends a SIP invite to the calling IMS network element. The SIP invite in this step can refer to the call request 1 of the foregoing embodiment.

[0395] Step 1108, the calling IMS network element sends a SIP invite to the called IMS network element. The SIP invite in this step can refer to the call request 2 of the foregoing embodiment.

[0396] Wherein, the step 807 and the step 808 can refer to the description of the step 604 and the step 605 in the embodiment shown in the foregoing Fig. 6, and details are not described herein again. The timer in the embodiment shown in the Fig. 6 can also be understood as an invite response message timer.

[0397] The step 1109, the called IMS network element sends an authentication authorization request (AA-Request, AAR) to the PCF network element.

[0398] The called IMS network element can send the AAR to the PCF network element. Correspondingly, the PCF network element receives the AAR sent by the called IMS network element. This step can refer to the step 803 in the embodiment shown in the foregoing Fig. 8.

[0399] The step 1110, the PCF network element sends an authentication authorization answer (AA-Answer, AAA) to the called IMS network element.

[0400] The PCF network element sends the AAA to the called IMS network element. Correspondingly, the called IMS network element receives the AAA sent by the PCF network element. This step can refer to the step 805 in the embodiment shown in the foregoing Fig. 8.

[0401] Optionally, the AAA carries the first time length for paging the called terminal device or the parameter information in the foregoing embodiment shown in the Fig. 6. Or, the AAA is used to indicate the first time length or the parameter information.

[0402] The step 1111, the called IMS network element sends the first time length for paging the called terminal device to the calling IMS network element.

[0403] The step 1112, the calling IMS network element sends prompt information to the calling terminal device.

[0404] The step 1113, the called IMS network element determines an invite response message timer based on a second time length.

[0405] Wherein, the second time length is obtained based on the first time length or the parameter information. This step can refer to the step 907 in the embodiment shown in the foregoing Fig. 9.

[0406] The step 1114, the called IMS network element sends a SIP invite to the UPF network element.

[0407] The step 1115, the UPF network element sends a DL data notification to the SMF network element.

[0408] The step 1116, the SMF network element sends an N1N2 message transmission to the AMF network element.

[0409] The step 1117, the AMF network element pages the called terminal device through an access network device.

[0410] Steps 1111 to 1117 can refer to the description of steps 1011 to 1017 in the foregoing embodiment shown in FIG. 10, which will not be repeated here. It can be understood that some steps may not correspond, for example, step 1113 can refer to step 1012 in the embodiment shown in FIG. 10, and for example, step 1112 can refer to step 1013 in the embodiment shown in FIG. 10, and so on.

[0411] It can be seen that, on the one hand, the called IMS network element receives the AAA or RAA sent by the PCF network element, and since the AAA or RAA is used to indicate the first information, the called IMS network element can obtain the first information in the call establishment process, so as to determine the second time length according to the first information. On the other hand, the called IMS network element controls the operation related to the call of the called terminal device through the second time length, and considers the enhanced paging mechanism / notification mechanism when determining the second time length, for example, needs to consider the first time length required when calling the terminal device through the enhanced paging mechanism / notification mechanism or the parameter information related to the enhanced paging mechanism / notification mechanism, which can reduce the problems such as the call being terminated by mistake or the invalid waiting of the calling terminal due to the mismatch between the second time length and the enhanced paging mechanism / notification mechanism. On the other hand, different parameter information can correspond to different first time lengths or second time lengths. For example, the time length (such as the first time length or the second time length) of the satellite access network mode is greater than the time length (such as the first time length or the second time length) of the non-satellite access network mode, so as to reserve a certain time length for the user corresponding to the called terminal device to perform the satellite operation, so as to improve the normal communication between the calling terminal device and the called terminal device.

[0412] The communication method in the embodiments of the present application is described above, and the communication device in the embodiments of the present application is described below. Referring to FIG. 12, one embodiment of the communication device 1200 in the embodiments of the present application can implement the functions of the first IMS network element / core network device / second IMS network element in the above-mentioned method embodiments, and thus can also implement the beneficial effects possessed by the above-mentioned method embodiments. In the embodiments of the present application, the communication device 1200 can be a communication device, or an integrated circuit or element inside the communication device, such as a chip. The communication device 1200 includes a transceiver unit 1201 and a processing unit 1202. Alternatively, the communication device 1200 includes a transceiver unit 1201.

[0413] In a possible implementation manner, the communication device 1200 is the first IMS network element in the foregoing embodiments shown in FIGS. 1 to 11, in which case the functions of each unit are as follows:

[0414] The transceiver unit 1201 is configured to receive the first information sent by the first core network element.

[0415] The processing unit 1202 is configured to determine the second time length based on the first information.

[0416] The first information is used to indicate a first time length for paging the first terminal device or parameter information. The parameter information can be understood as parameter information affecting the time length for paging / calling the first terminal device. The parameter information includes at least one of the following: whether the first terminal device activates a first mechanism / notice, whether the first terminal has a first capability, a policy of the first mechanism / notice / capability, an access network mode of the first terminal device, a star-facing time length of the first terminal device, etc. The second time length is used to control an operation related to the call of the first terminal device.

[0417] Optionally, the operation related to the call of the first terminal device includes: terminating the call of the first terminal device, or re-sending a call request for calling the first terminal device.

[0418] Optionally, the transceiver 1201 is further configured to send, to a fourth core network element, a call request for calling the first terminal device; and the processing unit 1202 is further configured to set / start a timer based on the second time length, and if the timer is timed out, terminate the call of the first terminal device or re-send the call request.

[0419] Optionally, the processing unit 1202 is specifically configured to determine the second time length based on the first time length, or the processing unit 1202 is specifically configured to determine the second time length based on the parameter information.

[0420] Optionally, the transceiver 1201 is further configured to send, to a second Internet Protocol Multimedia Subsystem (IMS) network element, the second time length.

[0421] Optionally, the second time length of the first terminal device in the case of activating the alert mechanism is different from the second time length of the first terminal device in the case of not activating the alert mechanism.

[0422] Optionally, in the case of activating the alert mechanism, the second time length is determined based on a paging policy of the alert mechanism and / or a star-facing time length.

[0423] Optionally, the paging policies of different alert mechanisms correspond to different second time lengths.

[0424] Optionally, the access network mode of the first terminal device includes: a satellite mode or a non-satellite mode, and the second time lengths of different access network modes are different.

[0425] In this embodiment, the operations performed by each unit in the communication device are similar to the description of the first IMS network element in the foregoing embodiments shown in FIGS. 1 to 11, and will not be described here again.

[0426] In this embodiment, the transceiver unit 1201 receives the first information sent by the core network device. The first information is used to indicate the first time length or parameter information for paging the first terminal device. The parameter information is related to at least one of the following: whether the first terminal device activates the alerting mechanism, the paging strategy of the alerting mechanism, the access network mode of the first terminal device, the star-facing time length of the first terminal device, and the like. Then, the second time length is determined based on the first information. The second time length is used to control the operation related to the call of the first terminal device. The enhanced paging mechanism / notification mechanism is considered when determining the second time length. For example, when calling the terminal device through the enhanced paging mechanism / notification mechanism, the first time length required or the parameter information related to the enhanced paging mechanism / notification mechanism needs to be considered when determining the second time length. This can reduce the problems such as the call being terminated incorrectly due to the mismatch between the second time length and the enhanced paging mechanism / notification mechanism (the IMS network element times out without receiving the response of the called terminal, but actually the core network is still paging the called terminal through the enhanced paging mechanism / notification mechanism), or the invalid waiting of the calling terminal (the IMS network element is still waiting for the response of the called terminal, but actually the paging of the called terminal by the core network has failed).

[0427] In another possible implementation manner, the communication apparatus 1200 is the first core network element in the foregoing embodiments shown in FIGS. 1 to 11. In this case, the functions of the units are as follows.

[0428] The processing unit 1202 is configured to determine the first information.

[0429] The transceiver unit 1201 is configured to send the first information to the first Internet Protocol Multimedia Subsystem (IMS) network element serving the first terminal device.

[0430] The first information is used to indicate the first time length or parameter information for paging the first terminal device. The parameter information can be understood as the parameter information affecting the time length of paging / calling the first terminal device. The parameter information includes at least one of the following: whether the first terminal device activates the first mechanism / notification, whether the first terminal has the first capability, the strategy of the first mechanism / notification / capability, the access network mode of the first terminal device, the star-facing time length of the first terminal device, and the like. The second time length is used to control the operation related to the call of the first terminal device.

[0431] Optionally, the first information includes the first time length. The processing unit 1202 is specifically configured to determine the first time length based on the parameter information.

[0432] Optionally, the transceiver unit 1201 is further configured to receive the second information sent by the second core network element. The second information is used to indicate the first time length.

[0433] Optionally, the transceiver unit 1201 is further configured to receive the parameter information sent by the second core network element.

[0434] Optionally, the communication apparatus is a first core network element, the first core network element is a unified data management function (UDM) network element or a policy control function (PCF) network element, and the second core network element is an access and mobility management function (AMF) network element.

[0435] Optionally, the second time length when the first terminal device activates the alerting mechanism is different from the second time length when the first terminal device does not activate the alerting mechanism.

[0436] Optionally, the second time length is determined based on a paging policy of the alerting mechanism and / or a satellite facing time length when the first terminal device activates the alerting mechanism.

[0437] Optionally, the paging policy of different alerting mechanisms corresponds to different second time lengths.

[0438] Optionally, the access network mode of the first terminal device includes a satellite mode or a non-satellite mode, and the second time length is different for different access network modes.

[0439] In this embodiment, the operations performed by the units in the communication apparatus are similar to the description of the core network device in the foregoing embodiments shown in FIGS. 1-11, and will not be described here again.

[0440] In this embodiment, the transceiver 1201 sends first information to the first IMS, and the first information is used to indicate a first time length or parameter information for paging the first terminal device. The parameter information is related to at least one of whether the first terminal device activates an alerting mechanism, a paging policy of the alerting mechanism, an access network mode of the first terminal device, a satellite facing time length of the first terminal device, and the like. Then, the second time length is determined based on the first information, and the second time length controls an operation related to a call of the first terminal device. When determining the second time length, the enhanced paging mechanism / notification mechanism is considered, for example, when calling the terminal device through the enhanced paging mechanism / notification mechanism, the first time length required or the parameter information related to the enhanced paging mechanism / notification mechanism needs to be considered when determining the second time length, which can reduce problems such as the call being terminated incorrectly (the IMS network element times out without receiving a response of the called terminal, but actually the core network is still paging the called terminal through the enhanced paging mechanism / notification mechanism) or invalid waiting of the calling terminal (the IMS network element is still waiting for a response of the called terminal, but actually the core network paging the called terminal has failed) due to the mismatch between the second time length and the enhanced paging mechanism / notification mechanism.

[0441] In another possible implementation manner, the communication apparatus 1200 is the second IMS network element in the foregoing embodiments shown in FIGS. 1-11, and in this case, the functions of the units are as follows:

[0442] The transceiver 1201 is configured to send a call request to the first IMS network element.

[0443] The transceiver 1201 is further configured to receive a second time length sent by the first IMS network element, the second time length being used for controlling an operation related to a call of the first terminal device, and the second time length being related to parameter information, which can be understood as parameter information affecting the time length of paging / calling the first terminal device. The parameter information includes at least one of the following: whether the first terminal device activates a first mechanism / indication, whether the first terminal device has a first capability, a policy of the first mechanism / indication / capability, an access network mode of the first terminal device, and a time length of aiming at a satellite of the first terminal device. The second time length is used for controlling the operation related to the call of the first terminal device.

[0444] Optionally, the transceiver 1201 is further configured to send prompt information to the second terminal device, the prompt information being used for prompting the second terminal device to wait for the call to be connected.

[0445] Optionally, the operation related to the call of the first terminal device includes terminating the call of the first terminal device or re-sending a call request for calling the first terminal device.

[0446] Optionally, the second time length of the first terminal device in the activated alert mechanism is different from the second time length of the first terminal device in the unactivated alert mechanism.

[0447] Optionally, in the activated alert mechanism, the second time length is determined based on a paging policy of the alert mechanism and / or a time length of aiming at a satellite.

[0448] Optionally, the paging policies of different alert mechanisms correspond to different second time lengths.

[0449] Optionally, the access network mode of the first terminal device includes a satellite mode or a non-satellite mode, and the second time lengths of different access network modes are different.

[0450] In this embodiment, the operations performed by each unit in the communication device are similar to the description of the second IMS network element in the foregoing embodiments shown in FIGS. 1 to 11, and will not be described here again.

[0451] In this embodiment, the first information is used to indicate the first time length or parameter information for paging the first terminal device. The parameter information is related to at least one of whether the first terminal device activates the alerting mechanism, the paging strategy of the alerting mechanism, the access network mode of the first terminal device, the star access time length of the first terminal device, and the like. Then, the second time length is determined based on the first information, and the second time length is used to control the operation related to the call of the first terminal device. When determining the second time length, the enhanced paging mechanism / notification mechanism is considered, for example, when calling the terminal device through the enhanced paging mechanism / notification mechanism, the first time length required or the parameter information related to the enhanced paging mechanism / notification mechanism needs to be considered, which can reduce the problems such as the call being terminated incorrectly (the IMS network element times out without receiving the response of the called terminal, but actually the core network is still paging the called terminal through the enhanced paging mechanism / notification mechanism) or the invalid waiting of the calling terminal (the IMS network element is still waiting for the response of the called terminal, but actually the core network has failed to page the called terminal) due to the mismatch between the second time length and the enhanced paging mechanism / notification mechanism.

[0452] Referring to FIG. 13, another schematic structural diagram of a communication apparatus 1300 provided in the present application is shown, which includes a logic circuit 1301 and an input / output interface 1302. The communication apparatus 1300 can be a chip or an integrated circuit.

[0453] The transceiver unit 1201 shown in FIG. 12 can be a communication interface, which can be the input / output interface 1302 in FIG. 13, and the input / output interface 1302 can include an input interface and an output interface. Alternatively, the communication interface can also be a transceiver circuit, which can include an input interface circuit and an output interface circuit. The processing unit 1202 shown in FIG. 12 can be the logic circuit 1301 in FIG. 13.

[0454] Optionally, in the case where the communication apparatus is the first IMS network element in the foregoing embodiments, the logic circuit 1301 is configured to perform at least one of the following: determining the second time length based on the first information, setting / starting a timer based on the second time length, and the like. The input / output interface 1302 is configured to perform at least one of the following: receiving the first information, sending / receiving a call request, sending the second time length, and the like.

[0455] Optionally, in the case where the communication apparatus is the core network device in the foregoing embodiments, the logic circuit 1301 is configured to perform at least one of the following: determining the first information, and the like. The input / output interface 1302 is configured to perform at least one of the following: sending the first information, sending / receiving a call request, paging the first terminal device through the access network device, and the like.

[0456] Optionally, in the case that the communication device is the second IMS network element in the foregoing embodiments, the input / output interface 1302 is configured to perform at least one of the following: receiving the second time length, sending / receiving the call request, sending the prompt information, and the like.

[0457] The logic circuit 1301 and the input / output interface 1302 can also perform other steps and achieve corresponding beneficial effects performed by the first IMS network element / the core network device / the second IMS network element in any embodiment, which will not be repeated here.

[0458] Optionally, the logic circuit 1301 can be a processing device, and the functions of the processing device can be partially or entirely implemented by software.

[0459] Optionally, the processing device can include a memory and a processor, where the memory is configured to store a computer program, and the processor is configured to read and execute the computer program stored in the memory to perform the corresponding processing and / or steps in any one of the method embodiments.

[0460] Optionally, the processing device can only include the processor. The memory for storing the computer program is located outside the processing device, and the processor is connected with the memory through a circuit / wire to read and execute the computer program stored in the memory. The memory and the processor can be integrated together or can be physically independent of each other.

[0461] Optionally, the processing device can be one or more chips or one or more integrated circuits. For example, the processing device can be one or more field-programmable gate arrays (FPGA), application specific integrated circuits (ASIC), system on chips (SoC), central processor units (CPU), network processors (NP), digital signal processors (DSP), micro controller units (MCU), programmable logic devices (PLD), or other integrated chips, or any combination of the above chips or processors.

[0462] Please refer to FIG. 14, the communication apparatus 1400 related to the above-mentioned embodiments provided by the embodiments of the present application, which can be specifically the communication apparatus in the above-mentioned embodiments as the first IMS network element / core network device / second IMS network element.

[0463] Wherein, a possible logical structure diagram of the communication apparatus 1400, the communication apparatus 1400 can include but not limited to at least one processor 1401 and a communication port 1402.

[0464] Wherein, the transceiver unit 1201 shown in FIG. 12 can be a communication interface, which can be the communication port 1402 in FIG. 14, the communication port 1402 can include an input interface and an output interface. Alternatively, the communication port 1402 can also be a transceiver circuit, which can include an input interface circuit and an output interface circuit.

[0465] Further optionally, the apparatus can also include at least one of a memory 1403, a bus, and in the embodiments of the present application, the at least one processor 1401 is used to control and process the actions of the communication apparatus 1400.

[0466] In addition, the processor 1401 can be a central processor unit, a general-purpose processor, a digital signal processor, an application-specific integrated circuit, a field programmable gate array or other programmable logic device, a transistor logic device, a hardware component or any combination thereof. It can implement or execute various exemplary logical blocks, modules and circuits described in combination with the disclosure. The processor can also be a combination of computing functions, such as one or more microprocessor combinations, digital signal processor and microprocessor combinations, etc. Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the above-mentioned system, apparatus and unit can refer to the corresponding process in the foregoing method embodiments, which will not be described here.

[0467] It can be understood that the present application does not limit the number of each component shown in FIG. 14. For example, the number of processors 1401, the number of communication ports 1402 and the number of memories 1403 can be one or more, respectively, which are not limited here.

[0468] It should be noted that the communication apparatus 1400 shown in FIG. 14 can be specifically used to implement the steps implemented by the first IMS network element / core network device / second IMS network element in the foregoing method embodiments, and achieve the corresponding technical effects of the first IMS network element / core network device / second IMS network element. The specific implementation mode of the communication apparatus shown in FIG. 14 can refer to the description in the foregoing method embodiments, which will not be described one by one here.

[0469] When the communication device is a chip applied to a terminal, the terminal chip implements the functions of the terminal in the method embodiments. The terminal chip receives information from other modules (such as a radio frequency module or an antenna) in the terminal, and the information is sent by the base station to the terminal; or the terminal chip sends information to other modules (such as a radio frequency module or an antenna) in the terminal, and the information is sent by the terminal to the base station. For example, in the case where the first device is a terminal, the terminal sending indication information can be understood as the process of the chip of the terminal outputting the indication information.

[0470] When the communication device is a module applied to a base station, the base station module implements the functions of the base station in the method embodiments. The base station module receives information from other modules (such as a radio frequency module or an antenna) in the base station, and the information is sent by the terminal to the base station; or the base station module sends information to other modules (such as a radio frequency module or an antenna) in the base station, and the information is sent by the base station to the terminal. The base station module here can be a baseband chip of the base station, or a DU or other module, and the DU here can be a DU under the open radio access network (O-RAN) architecture. For example, in the case where the first device is a base station, the base station sending indication information can be understood as the process of the chip of the base station outputting the indication information.

[0471] The method steps in the embodiments of the present application can be implemented in hardware or in software instructions executable by a processor. The software instructions can be composed of corresponding software modules, which can be stored in a random access memory, a flash memory, a read-only memory, a programmable read-only memory, an erasable programmable read-only memory, an electrically erasable programmable read-only memory, a register, a hard disk, a mobile hard disk, a CD-ROM, or any other form of storage medium well known in the art. An exemplary storage medium is coupled to a processor, so that the processor can read information from the storage medium and write information to the storage medium. The storage medium can also be an integral part of the processor. The processor and the storage medium can be located in an ASIC. In addition, the ASIC can be located in a base station or a terminal. The processor and the storage medium can also exist as discrete components in the base station or the terminal.

[0472] In the above embodiments, all or part of the embodiments can be implemented by software, hardware, firmware or any combination thereof. When implemented by software, all or part of the embodiments can be implemented in the form of a computer program product. The computer program product includes one or more computer programs or instructions. When the computer programs or instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of the present 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 apparatus. The computer programs or instructions can be stored in a computer readable storage medium or transmitted from one computer readable storage medium to another computer readable storage medium, for example, the computer programs or instructions can be transmitted from one website site, computer, server or data center to another website site, computer, server or data center through wired or wireless manner. The computer readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server, data center and the like integrated with one or more available media. The available media can be a magnetic medium, such as a floppy disk, a hard disk, a magnetic tape; or an optical medium, such as a digital video disc; or a semiconductor medium, such as a solid state disk. The computer readable storage medium can be a volatile or non-volatile storage medium, or can include both volatile and non-volatile storage media.

[0473] In various embodiments of the present application, the terms and / or descriptions of different embodiments are consistent and can be referred to each other if there is no special description and logical conflict, and the technical features in different embodiments can be combined to form new embodiments according to their inherent logical relationship.

Claims

1. A communication method characterized by comprising: The method is applied to a first Internet Protocol Multimedia Subsystem, IMS, network element, and the method comprises: receiving first information sent by a first core network network element, the first information being used to indicate a first time length for paging a first terminal device or parameter information, the parameter information comprising at least one of the following: whether the first terminal device activates an alerting mechanism, a paging strategy of the alerting mechanism, an access network mode of the first terminal device, or a time length for which the first terminal device is in a star state; determining a second time length based on the first information, the second time length being used to control an operation related to a call of the first terminal device.

2. The method of claim 1, wherein, The operation related to the call of the first terminal device comprises: terminating the call of the first terminal device, or resending a call request for calling the first terminal device.

3. The method according to claim 1 or 2, characterized in that, The method further comprises: sending, to a fourth core network network element, a call request for calling the first terminal device; setting or starting a timer based on the second time length, and if the timer expires, terminating the call of the first terminal device or resending the call request.

4. The method according to any one of claims 1 to 3, characterized in that, The determining of the second time length based on the first information comprises: determining the second time length based on the first time length, or determining the second time length based on the parameter information.

5. The method according to any one of claims 1 to 4, characterized in that, The method further comprises: sending the second time length to a second IMS network element.

6. A communication method characterized by comprising: The method is applied to a first core network network element, and the method comprises: determining first information, the first information being used to indicate a first time length for paging a first terminal device or parameter information, the parameter information comprising at least one of the following: whether the first terminal device activates an alerting mechanism, a paging strategy of the alerting mechanism, an access network mode of the first terminal device, or a time length for which the first terminal device is in a star state; sending the first information to a first Internet Protocol Multimedia Subsystem, IMS, network element serving the first terminal device.

7. The method of claim 6, wherein, The first information comprises the first time length. The determining of the first information comprises: determining the first time length based on the parameter information.

8. The method of claim 6, wherein, The method further comprises: receiving second information sent by a second core network network element, the second information being used to indicate the first time length.

9. The method according to any one of claims 6 to 8, characterized in that, The method further comprises: receiving the parameter information sent by the second core network network element.

10. The method according to claim 8 or 9, characterized in that, The first core network network element is a Unified Data Management, UDM, network element or a Policy Control Function, PCF, network element, and the second core network network element is an Access and Mobility Management Function, AMF, network element.

11. A communication method, comprising: The method is applied to a second IMS network element, and the method comprises: sending a call request to a first IMS network element; receiving a second time length sent by the first IMS network element, the second time length being used to control an operation related to a call of a first terminal device, the second time length being related to parameter information, the parameter information comprising at least one of the following: whether the first terminal device activates an alerting mechanism, a paging strategy of the alerting mechanism, an access network mode of the first terminal device, or a time length for which the first terminal device is in a star state.

12. The method of claim 11, wherein, The method further comprises: based on the second time length, sending prompt information to a second terminal device, the prompt information being used to prompt the second terminal device to wait for a call to be connected.

13. The method according to claim 11 or 12, characterized in that, The operation related to the call of the first terminal device comprises terminating the call of the first terminal device, or re-sending a call request for calling the first terminal device.

14. The method according to any one of claims 1 to 13, characterized in that, The second time length when the first terminal device activates the alert mechanism is different from the second time length when the first terminal device does not activate the alert mechanism.

15. The method of claim 14, wherein, The second time length when the first terminal device activates the alert mechanism is determined based on a paging policy of the alert mechanism and / or the first time length.

16. The method according to any one of claims 1 to 15, characterized in that, Different paging policies of the alert mechanism correspond to different second time lengths.

17. The method of any one of claims 1 to 16, wherein, The access network mode of the first terminal device comprises a satellite mode or a non-satellite mode, and the second time length is different for different access network modes.

18. A communications device, characterized by The communication device comprises a processing unit and a transceiver unit. The processing unit and the transceiver unit are configured to perform the method of any one of claims 1-17.

19. A communications device, characterized by The chip or chip system is configured to perform the method of any one of claims 1-16.

20. A chip or chip system, characterized by The storage medium stores a computer program or instructions, and when the computer program or instructions are executed by the communication device, the method of any one of claims 1-17 is implemented.

21. A communication system, characterized by The instructions, when executed on a computer, cause the computer to perform the method of any one of claims 1-17.

22. A readable storage medium, characterized by, The instructions, when executed on a computer, cause the computer to perform the method of any one of claims 1-17.

23. A computer program product, characterised in that, ​

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