Communication method and device

Abstract

The embodiment of the invention provides a communication method and device. The terminal equipment sends a registration request message, wherein the registration request message is used for providing inaccessible time information of the first event to the network; if the reply message is not received or the registration rejection message is received, repeatedly sending the registration request message until the starting point of the unreachable time or the first preset duration is reached; and when a starting point of the unreachable time or a first preset duration is reached, executing the first event. The terminal device sets the time for stopping attempting registration or sets the time length for attempting registration so as to avoid delay of execution of the first event due to attempting registration all the time.

Description

Technical Field

[0001] The present application relates to the field of communication technology, and in particular to a communication method and a device thereof. Background Art

[0002] In order to avoid interruption of the registration process of the terminal device when the modem is silently reset or the operating system (OS) is updated, a storage method for seamless context switching is provided. Specifically, when the modem is silently reset or the OS is updated, the terminal device stores the mobile management (MM) context and session management (SM) context in the cache to the non-volatile memory (NV) or the universal subscriber identity module (USIM). When the terminal device recovers from the modem silent reset or OS update, the MM context and SM context in the NV or USIM are read to initiate registration. In addition, the terminal device is required to report the unavailability period to the network device. Based on the unavailability period, the network device retains the MM context and SM context of the terminal device during this period and does not perform implicit deregistration. In this way, the terminal device can be kept in the registered state when the modem is silently reset or the OS is updated.

[0003] When the terminal device reports the unreachable time to the network device, the report may fail. For example, the network link quality is poor, resulting in multiple registration attempts without receiving a response from the network and being unable to determine whether the report is successful; or the network rejects the report with specific reasons such as Roaming not allowed in this tracking area, No suitable cells in tracking area, Congestion, etc. If the terminal device keeps trying to register, it will affect the modem silent reset or OS update.

[0004] After the terminal device fails to register, what to do next is something that needs to be considered. Summary of the invention

[0005] The embodiment of the present application provides a communication method and apparatus thereof, which are used to propose operations of a terminal device after registration fails.

[0006] In the first aspect, the present application provides a communication method, which can be executed by a first communication device, or by other devices including the functions of the first communication device, or by a chip system (or, chip) or other functional modules, which can realize the functions of the first communication device, and the chip system or functional module is, for example, set in the first communication device. Take the method executed by the first communication device, which is a terminal device, as an example for introduction: sending a registration request message, the registration request message is used to provide the unreachable time information of the first event to the network; if no reply message is received or a registration rejection message is received, the registration request message is repeatedly sent until the preset time is reached; wherein the preset time is the starting point of the unreachable time; when the preset time is reached, the first event is executed.

[0007] In this embodiment, the terminal device keeps trying to register before the preset time is reached, and stops trying to register when the preset time is reached. The terminal device sets the time to stop trying to register to avoid delaying the execution of the first event by constantly trying to register.

[0008] In the second aspect, the present application provides a communication method, which can be executed by a first communication device, or by other devices including the functions of the first communication device, or by a chip system (or, chip) or other functional modules, which can realize the functions of the first communication device, and the chip system or functional module is, for example, set in the first communication device. Take the method executed by the first communication device, which is a terminal device, as an example for introduction: send a registration request message, the registration request message is used to provide the unreachable time information of the first event to the network; if no reply message is received or a registration rejection message is received, repeat the registration request message until the first preset duration is reached; when the first preset duration is reached, execute the first event.

[0009] In this embodiment, the terminal device keeps trying to register before the first preset time is reached, and stops trying to register when the first preset time is reached. The terminal device sets the time for trying to register to avoid delaying the execution of the first event by constantly trying to register.

[0010] In a possible implementation, the start time of the first preset duration is related to the time when the registration request message is sent for the first time, or is related to the time when the registration request message is sent for the first time and it is determined that no reply message is received or a registration rejection message is received.

[0011] In a possible implementation manner, the first preset duration is the duration of the registration attempt.

[0012] The following multiple possible implementations may be applicable to the above-mentioned first aspect and second aspect.

[0013] In a possible implementation, when the preset time is reached or when the first preset duration is reached, if no reply message is received for the last registration request message sent or a registration rejection message is received, before executing the first event, it also includes: maintaining a registered state and storing first context information in a first storage space; wherein the first context information is used for mobile management and / or session management; when shutting down or executing the first event, the data in the first storage space will not be lost.

[0014] In this implementation, before the terminal device sends a registration request message for the first time, the network device maintains the context information of the terminal device in the registration state. After the terminal device sends a registration request message for the first time or for multiple subsequent times, if the network link is not good and the network device does not receive the registration request message, the network device will still maintain the context information of the terminal device. If the network device receives a registration request message and refuses to register, but the reason value for the refusal makes the terminal device still in the registration state and does not enter the deregistration state, the network device will still maintain the context information of the terminal device. The network device maintains the context for a long time, which can generally last until the execution of the first event is completed. Therefore, before the first event is executed, the terminal device stores the first context information in the first storage space, which will not be deleted when the first event is executed, so that the previously negotiated context can be reused after the first event is executed, without renegotiating with the network, which can save signaling overhead, speed up the business process, and will not interrupt the session or business.

[0015] In one possible implementation, when the preset time is reached or when the first preset duration is reached, if no reply message is received for the last registration request message sent or a registration rejection message is received, before executing the first event, it also includes: maintaining a registered state, and determining whether to store the first context information in a first storage space based on a first value and a second value; wherein the first value is used to indicate the remaining duration of the deregistration timer, and the second value is the duration of the first event; the first context information is used for mobile management and / or session management; when shutting down or executing the first event, the data in the first storage space will not be lost.

[0016] In one possible implementation, determining whether to store the first context information in the first storage space is based on a first value and a second value, including: if the first value is greater than or equal to the second value, storing the first context information in the first storage space; if the first value is less than the second value, not storing the first context information in the first storage space; or, if the first value is greater than the second value, storing the first context information in the first storage space; if the first value is less than or equal to the second value, not storing the first context information in the first storage space.

[0017] In this implementation, if the remaining duration of the deregistration timer is greater than the duration of the first event, the network device also maintains the context of the terminal device when the first event is completed. The terminal device can send a registration request message to the network device when the first event is completed. The network device does not perform implicit deregistration on the terminal device after receiving the registration request message of the terminal device, and the network device continues to maintain the context information of the terminal device. Therefore, the terminal device stores the first context information in the first storage space. After the first event is completed, the previously negotiated context can be reused without renegotiating with the network, which can save signaling overhead, speed up the service process, and will not interrupt the session or service. If the remaining duration of the deregistration timer is less than the duration of the first event, the network device has performed deregistration when the first event is completed, and the context of the terminal device is not maintained. The terminal device does not need to store the first context information in the first storage space, which can save storage space of the terminal device.

[0018] In one possible implementation, when the preset time is reached or when the first preset duration is reached: if a registration rejection message is received for the last registration request message sent, the first value is the maximum value of the de-registration timer; if no reply message is received for the last registration request message sent, the first value is determined based on the maximum value of the de-registration timer, the time when the first event starts to execute, and the time when the last reply message is received; wherein the last reply message received is a registration acceptance message received before the first sending of the registration request message, or a registration rejection message received after the first sending of the registration request message.

[0019] In this implementation, the network device sends a registration rejection message to the terminal device and starts a deregistration timer. Ignoring the transmission delay, when the terminal device receives the registration rejection message, the remaining duration of the deregistration timer is the maximum value Tmax, that is, the first value is Tmax. If the terminal device starts to execute the first event after a period of time, the remaining duration of the deregistration timer is: the maximum value of the deregistration timer - (the time t2 when the first event starts to execute - the time t3 when the last reply message is received), that is, the first value is Tmax-(t2-t3).

[0020] In one possible implementation, when the preset time is reached or when the first preset duration is reached, if no reply message is received for the last registration request message sent or a registration rejection message is received, before executing the first event, it also includes: maintaining a registered state and storing the first part of information in the first context information in a first storage space; wherein the first context information is used for mobile management and / or session management, and the first part of information is used for security verification; when shutting down or executing the first event, the data in the first storage space will not be lost.

[0021] In this implementation, the first part of information includes the first part of information for security verification, and also includes the second part of information other than that for security verification. The terminal device will not store the second part of information in the first storage space, so as to avoid wasting storage resources. The first part of information includes but is not limited to the currently defined MM contexts such as the Globally Unique Temporary UE Identity (GUTI) and security context, which is used to reuse the previously negotiated security context after the first event is completed, so as to speed up the registration process.

[0022] In a possible implementation manner, when executing the first event, the method further includes: entering a deregistration state.

[0023] In a possible implementation manner, the first event includes: operating system update and / or modem reset.

[0024] In a possible implementation, before executing the first event, it also includes: if a registration acceptance message is received, remain in the registered state, and store the first context information in the first storage space; wherein the first context information is used for mobile management and / or session management; when shutting down or executing the first event, the data in the first storage space will not be lost.

[0025] In the third aspect, the present application provides a communication method, which can be executed by a first communication device, or by other devices including the functions of the first communication device, or by a chip system (or, chip) or other functional modules, which can realize the functions of the first communication device, and the chip system or functional module is, for example, set in the first communication device. Take the method executed by the first communication device, which is a terminal device, as an example for introduction: send a registration request message, the registration request message is used to provide the unreachable time information of the first event to the network; if no reply message is received or a registration rejection message is received, remain in the registered state, and store the first context information in the first storage space; wherein the first context information is used for mobile management and / or session management; when shutting down or executing the first event, the data in the first storage space will not be lost; execute the first event.

[0026] In a possible implementation manner, a registration attempt counter in the first context information in the first storage space is reset to 0.

[0027] In the fourth aspect, the present application provides a communication method, which can be executed by a first communication device, or by other devices including the functions of the first communication device, or by a chip system (or, chip) or other functional modules, which can realize the functions of the first communication device, and the chip system or functional module is, for example, set in the first communication device. Take the method as an example that the first communication device is executed by the first communication device, and the first communication device is a terminal device: send a registration request message, and the registration request message is used to provide the unreachable time information of the first event to the network; if no reply message is received or a registration rejection message is received, remain in the registered state, and determine whether to store the first context information in the first storage space based on the first value and the second value; wherein the first value is used to indicate the remaining duration of the deregistration timer, and the second value is the duration of the first event; the first context information is used for mobile management and / or session management; when shutting down or executing the first event, the data in the first storage space will not be lost; execute the first event.

[0028] In a possible implementation, determining whether to store the first context information in the first storage space based on the first value and the second value includes:

[0029] If the first value is greater than or equal to the second value, storing the first context information in a first storage space;

[0030] If the first value is smaller than the second value, the first context information is not stored in the first storage space.

[0031] In one possible implementation, if a registration rejection message is received, the first value is the maximum value of the de-registration timer; if no reply message is received, the first value is determined based on the maximum value of the de-registration timer, the time when the first event starts to execute, and the time when the last reply message was received before the registration request message was sent.

[0032] In the fifth aspect, the present application provides a communication method, which can be executed by a first communication device, or by other devices including the functions of the first communication device, or by a chip system (or, chip) or other functional modules, which can realize the functions of the first communication device, and the chip system or functional module is, for example, set in the first communication device. Take the method executed by the first communication device, which is a terminal device, as an example for introduction: send a registration request message, the registration request message is used to provide the unreachable time information of the first event to the network; if no reply message is received or a registration rejection message is received, remain in the registered state, and store the first part of the information in the first context information in the first storage space; wherein the first context information is used for mobile management and / or session management, and the first part of the information is used for security verification; when shutting down or executing the first event, the data in the first storage space will not be lost; execute the first event.

[0033] In a possible implementation manner, when executing the first event, the method further includes: entering a deregistration state.

[0034] The following multiple possible implementations may be applicable to the third to fifth aspects mentioned above.

[0035] In one possible implementation, if a registration acceptance message is received, the registration state is maintained and the first context information is stored in a first storage space; wherein the first context information is used for mobile management and / or session management; when shutting down or executing the first event, the data in the first storage space will not be lost.

[0036] In a possible implementation manner, the first event includes: operating system update and / or modem reset.

[0037] The beneficial effects of the third to fifth aspects can be referred to the introduction of various possible implementation methods in the first aspect, and will not be repeated here.

[0038] In a sixth aspect, a communication device is provided, and the communication device may be a terminal device as described in the above-mentioned various aspects. The communication device has the functions of the above-mentioned terminal device. The communication device is, for example, a terminal device, or a larger device including a terminal device, or a functional module in a terminal device, such as a baseband device or a chip system. In an optional implementation, the communication device includes a baseband device and a radio frequency device. In another optional implementation, the communication device includes a processing unit (sometimes also referred to as a processing module) and a transceiver unit (sometimes also referred to as a transceiver module). The transceiver unit can implement a sending function and a receiving function. When the transceiver unit implements the sending function, it can be referred to as a sending unit (sometimes also referred to as a sending module), and when the transceiver unit implements the receiving function, it can be referred to as a receiving unit (sometimes also referred to as a receiving module). The sending unit and the receiving unit may be the same functional module, which is called a transceiver unit, and the functional module can implement a sending function and a receiving function; or, the sending unit and the receiving unit may be different functional modules, and the transceiver unit is a general term for these functional modules.

[0039] In one possible implementation, the communication device also includes a storage unit (sometimes also referred to as a storage module), and the processing unit is used to couple with the storage unit and execute the program or instructions in the storage unit, so as to enable the communication device to perform the functions of the terminal device described in the above aspects.

[0040] In a possible implementation manner, the transceiver unit is used to send a registration request message, where the registration request message is used to provide unreachable time information of the first event to the network.

[0041] In a possible implementation, the processing unit is used to determine whether a preset time is reached, and when the preset time is reached, execute the first event; wherein the preset time is the starting point of the unreachable time.

[0042] In a possible implementation, the processing unit is configured to determine whether a first preset duration has been reached, and execute the first event when the first preset duration has been reached.

[0043] In one possible implementation, the processing unit is used to remain in a registered state and store first context information in a first storage space when the preset time is reached or the first preset duration is reached, if no reply message is received for the last registration request message sent or a registration rejection message is received; wherein the first context information is used for mobile management and / or session management; and when the power is turned off or the first event is executed, the data in the first storage space will not be lost.

[0044] In a possible implementation manner, the processing unit is configured to reset a registration attempt counter in the first context information to 0.

[0045] In one possible implementation, the processing unit is used to remain in the registered state and determine whether to store the first context information in the first storage space based on the first value and the second value when the preset time is reached or the first preset duration is reached if no reply message is received for the last registration request message sent or a registration rejection message is received; wherein the first value is used to indicate the remaining duration of the deregistration timer, and the second value is the duration of the first event.

[0046] In a possible implementation, the processing unit is specifically configured to store the first context information in a first storage space if the first value is greater than or equal to the second value; and not store the first context information in the first storage space if the first value is less than the second value.

[0047] In one possible implementation, the processing unit is used to maintain the registration state and store the first part of information in the first context information in the first storage space when the preset time is reached or the first preset duration is reached, if no reply message is received for the last registration request message sent or a registration rejection message is received; wherein the first part of information is used for security verification.

[0048] In a possible implementation, the processing unit is configured to, if receiving a registration acceptance message, remain in a registration state and store the first context information in a first storage space.

[0049] In a seventh aspect, a communication device is provided, which may be a terminal device, or a chip or chip system used in a terminal device. The communication device includes a communication interface and a processor, and optionally, a memory. The memory is used to store a computer program, and the processor is coupled to the memory and the communication interface. When the processor reads the computer program or instruction, the communication device executes the method executed by the terminal device in the above aspects.

[0050] In an eighth aspect, a communication device is provided, comprising a processor and, optionally, a memory; the processor and the memory are coupled; the memory is used to store computer programs or instructions; the processor is used to execute part or all of the computer programs or instructions in the memory, and when the part or all of the computer programs or instructions are executed, it is used to implement the functions of the terminal device in the above-mentioned various aspects and any possible implementation method of each aspect.

[0051] In a possible implementation, the apparatus may further include a transceiver, the transceiver being configured to send a signal processed by the processor or receive a signal input to the processor. The transceiver may perform a sending action or a receiving action performed by the terminal device in any of the above aspects and any possible implementations of the various aspects.

[0052] In a possible implementation, the processing unit in the sixth aspect may be implemented by the processor, the storage unit in the sixth aspect may be implemented by the memory, and the transceiver unit in the sixth aspect may be implemented by the transceiver.

[0053] In a ninth aspect, a communication system is provided, comprising a network device and a terminal device, wherein the terminal device is used to execute the method executed by the terminal device as described in the above aspects, and the network device is used to interact with the terminal device. For example, the terminal device can be implemented by the communication device as described in the sixth aspect.

[0054] In a tenth aspect, a computer-readable storage medium is provided, wherein the computer-readable storage medium is used to store computer programs or instructions, which, when executed, enable the methods described in the above aspects to be implemented.

[0055] According to an eleventh aspect, a computer program product comprising instructions is provided, which, when executed on a computer, enables the methods described in the above aspects to be implemented.

[0056] In a twelfth aspect, a chip system is provided, comprising a processor and an interface, wherein the processor is used to call and execute instructions from the interface so that the chip system implements the methods in each of the above aspects. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1a A schematic diagram of the architecture of a communication system provided for this application;

[0058] Figure 1b A schematic diagram of the architecture of a communication system provided for this application;

[0059] Figure 2 A flow chart of a communication method provided by this application;

[0060] Figure 3 A time allocation diagram provided for this application;

[0061] Figure 4 A flow chart of a communication method provided by this application;

[0062] Figure 5 A flow chart of a communication method provided by this application;

[0063] Figure 6A flow chart of a communication method provided by this application;

[0064] Figure 7 A structural diagram of a communication device provided for this application;

[0065] Figure 8 A structural diagram of a communication device provided in this application. DETAILED DESCRIPTION

[0066] The technical solution of the present application can be applied to various wireless communication systems, and can be applied to, but not limited to, the fourth generation mobile communication technology (the 4th generation, 4G) system (also known as the long term evolution (long term evolution, LTE) system), 5G system (also known as the new radio (new radio, NR) system), or can also be applied to the next generation mobile communication system or other similar communication systems (such as the sixth generation mobile communication technology (the 6th generation, 6G) system), etc., without specific restrictions. In addition, the technical solution provided in the embodiment of the present application can be applied to device-to-device (D2D) scenarios, such as NR-D2D scenarios, etc., or can be applied to V2X scenarios, such as NR-V2X scenarios, etc. For example, it can be used in the fields of intelligent driving, assisted driving, or intelligent connected vehicles. For another example, the technical solution provided in the embodiment of the present application can also be applied to factory manufacturing scenarios, etc.

[0067] For example, Figure 1a This is a schematic diagram of a 5G communication system architecture that can be applied to this application. Specifically, Figure 1a Schematic diagram of 5G network architecture based on service-oriented architecture.

[0068] For example, Figure 1b This is another 5G communication system architecture diagram that can be applied to this application. Specifically, Figure 1b Schematic diagram of point-to-point 5G architecture. Figure 1a and Figure 1b The main difference is that Figure 1a The interfaces between the various network elements in the system are service-oriented interfaces. Figure 1b The interfaces between network elements are point-to-point interfaces.

[0069] Figure 1a and Figure 1bThe 5G network architecture shown may include a terminal device part, an access network part, and a core network part. Optionally, it also includes a data network (DN) and an application function (AF) network element part. The terminal accesses the core network through the access network, and the core network communicates with the DN or AF. The functions of some of the network elements are briefly introduced below.

[0070] Terminal device, also known as user equipment (UE), is a device with wireless transceiver function, which can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; it can also be deployed on the water (such as ships); it can also be deployed in the air (such as airplanes, balloons and satellites). The terminal device can be a mobile phone, a tablet computer (pad), a computer with wireless transceiver function, a virtual reality (VR) terminal, an augmented reality (AR) terminal, a wireless terminal in industrial control, a wireless terminal in self-driving, a wireless terminal in remote medical, a wireless terminal in smart grid, a wireless terminal in transportation safety, a wireless terminal in smart city, a wireless terminal in smart home, etc.

[0071] The (R)AN device in this application is a device that provides wireless communication functions for terminal devices, and the (R)AN device is also called an access network device. The RAN devices in this application include but are not limited to: the next generation base station (g nodeB, gNB) in 5G, evolved node B (evolved node B, eNB), radio network controller (radio network controller, RNC), node B (node ​​B, NB), base station controller (base station controller, BSC), base transceiver station (base transceiver station, BTS), home base station (for example, home evolved nodeB, or home node B, HNB), baseband unit (baseBand unit, BBU), transmission point (transmitting and receiving point, TRP), transmission point (transmitting point, TP), mobile switching center, etc. In systems using different wireless access technologies, the names of devices with base station functions may be different. For example, in the fifth generation (5G) system, it is called RAN or gNB (5G NodeB); in the LTE system, it is called evolved NodeB (eNB or eNodeB); in the third generation (3G) system, it is called Node B, etc.

[0072] Data network DN can deploy multiple services and provide data and / or voice services to terminal devices. For example, DN is the private network of a smart factory. The sensors installed in the workshop of the smart factory can be terminal devices. Sensors and control servers are deployed in DN, and the control server can provide services for sensors. Sensors can communicate with the control server, obtain instructions from the control server, and transmit the collected sensor data to the control server according to the instructions. For another example, DN is the internal office network of a company. The mobile phones or computers of the company's employees can be terminal devices. The employees' mobile phones or computers can access information and data resources on the company's internal office network.

[0073] The application network element mainly supports interaction with the 3rd Generation Partnership Project (3GPP) core network to provide services, such as influencing data routing decisions, policy control functions, or providing some third-party services to the network side. In the 5G communication system, the application network element can be an application function (AF) network element. In future communication systems, the application network element can still be an AF network element, or it can have other names, which are not limited in this application.

[0074] The core network may include one or more of the following network elements:

[0075] The access management network element (also called the mobility management network element) is a control plane network element provided by the operator network, which is responsible for the access control and mobility management of the terminal device accessing the operator network, such as mobile state management, allocation of user temporary identity, authentication and user functions. In the 5G communication system, the access management network element can be an access and mobility management function (AMF) network element. In future communication systems, the access management network element can still be an AMF network element, or it can have other names, which are not limited in this application.

[0076] The session management network element is mainly responsible for session management in the mobile network, such as session establishment, modification, and release. Specific functions include allocating IP addresses to users, selecting user plane network elements that provide message forwarding functions, etc. In the 5G communication system, the session management network element can be a session management function (SMF) network element. In future communication systems, the session management network element can still be an SMF network element, or it can have other names, which are not limited in this application.

[0077] The user plane network element is responsible for forwarding and receiving user data in the terminal device. User data can be received from the data network and transmitted to the terminal device through the access network device; the user plane network element can also receive user data from the terminal device through the access network device and forward it to the data network. The transmission resources and scheduling functions that provide services to the terminal devices in the user plane network element are managed and controlled by the SMF network element. In the 5G communication system, the user plane network element can be a user plane function (UPF) network element. In future communication systems, the user plane network element can still be a UPF network element, or it can have other names, which are not limited in this application.

[0078] Data management network element, used for generating authentication credentials, user identification processing (such as storing and managing user permanent identities, etc.), access control and contract data management, etc. In the 5G communication system, the data management network element can be a unified data management (UDM) network element. In future communication systems, unified data management can still be a UDM network element, or it can have other names, which are not limited in this application.

[0079] The policy control network element mainly supports providing a unified policy framework to control network behavior, provides policy rules to the control layer network functions, and is responsible for obtaining user contract information related to policy decisions. In the 4G communication system, the policy control network element can be a policy and charging rules function (PCRF) network element. In the 5G communication system, the policy control network element can be a policy control function (PCF) network element. In future communication systems, the policy control network element can still be a PCF network element, or it can have other names, which are not limited in this application.

[0080] The network storage network element can be used to provide network element discovery function and provide network element information corresponding to the network element type based on the request of other network elements. NRF also provides network element management services, such as network element registration, update, deregistration, network element status subscription and push, etc. In the 5G communication system, the network storage network element can be a network repository function (NRF) network element. In future communication systems, the network storage network element can still be an NRF network element, or it can have other names, which are not limited in this application.

[0081] The network exposure function network element can be used to provide services and capabilities provided by 3GPP network function devices for securely opening them to the outside. In a 5G communication system, the network exposure function network element can be a network exposure function (NEF) network element. In future communication systems, the network exposure function network element can still be a NEF network element, or it can have other names, which are not limited in this application.

[0082] The network slice selection network element can be used to select a suitable network slice for the terminal's service. In a 5G communication system, the network slice selection network element may be a network slice selection function (NSSF) network element. In future communication systems, the network open function network element may still be an NSSF network element, or it may have other names, which are not limited in this application.

[0083] The network data analysis network element can collect data from various network functions (NF), such as policy control network elements, session management network elements, user plane network elements, access management network elements, and application function network elements (through network capability exposure function network elements), and perform analysis and prediction. In the 5G communication system, the network data analysis network element can be a network data analysis function (NWDAF). In future communication systems, the network exposure function network element can still be an NWDAF network element, or it can have other names, which are not limited in this application.

[0084] The data storage network element is responsible for storing structured data information, including contract information, policy information, and network data or service data defined in a standard format. In the 5G communication system, the data storage network element can be a unified data repository (UDR). In future communication systems, the network open function network element can still be a UDR network element, or it can have other names, which are not limited in this application.

[0085] It is understandable that the above network element or function can be a network element in a hardware device, a software function running on dedicated hardware, or a virtualized function instantiated on a platform (e.g., a cloud platform). In a possible implementation, the above network element or function can be implemented by one device, or by multiple devices together, or can be a functional module in one device, which is not specifically limited in the embodiments of the present application.

[0086] The current protocol allows the terminal device to store the mobile management MM context and session management SM context in the cache to the non-volatile memory NV or the global user identity card USIM before performing a modem silent reset or OS update. When the terminal device recovers from the modem silent reset or OS update, it reads the MM context and SM context in the NV or USIM and initiates mobile registration. In addition, the terminal device is allowed to report the unavailability period to the network device through a registration request message before performing a modem silent reset or OS update. Based on the unavailability period, the network device retains the MM context and SM context of the terminal device during this period and does not perform implicit deregistration. In this way, the terminal device remains in the registered state when performing a modem silent reset or OS update.

[0087] The terminal device reports the unreachable time to the network device through the registration request message. The registration may be successful or unsuccessful. For example, the poor quality of the network link may result in multiple registration attempts without receiving a response from the network, or the registration is rejected by some reason values. For example, the reason value is: roaming not allowed in this tracking area, no suitable cells in the tracking area, congestion, etc.

[0088] On the one hand, for different situations, it is necessary to consider how the terminal device stores MM and SM contexts and reasonably utilizes storage resources. On the other hand, after being rejected by a certain reason value, the terminal device may enter the deregistration state or remain in the registration state. The registration state may be an attempt to register update state or a public land mobile network (PLMN) search state. If the terminal device does not enter the deregistration state, it will continue to try to register. A possible implementation method of attempting to register is: multiple different time intervals are set in the terminal device, such as 30s, 2 minutes, 5 minutes, etc., and a registration attempt counter is also set. The terminal device first selects a shorter time interval for registration attempts. After the number of attempts reaches the value set by the registration attempt counter, it selects a larger time interval for registration attempts. After reaching the registration attempt counter, it selects a larger time interval for registration attempts. If the terminal device continues to attempt to register, it will delay the modem silent reset or OS update process.

[0089] Based on this, the present application proposes a variety of communication methods: introducing the operations of the terminal device for storing MM and SM contexts, and the operations for registration attempts in the case of successful or failed registration.

[0090] In order to better describe the embodiments of the present application, the method provided by the embodiments of the present application is described below in conjunction with the accompanying drawings. Unless otherwise specified in the following text, the steps indicated by dotted lines in the accompanying drawings corresponding to the various embodiments of the present application are all optional steps.

[0091] Below, some terms or concepts in the embodiments of the present application are explained to facilitate understanding by those skilled in the art.

[0092] 1) In the embodiments of the present application, "when **" can be replaced by: if **, in ** case, at ** time. For example, "if registration fails" can be replaced by: when registration fails, or, in the case of registration failure.

[0093] 2) In the embodiments of the present application, method a1, method b1, method c1, method d1, method a2, method b2, method c2 and method d2, etc., the methods are numbered only for the convenience of description, without any restriction on the order of sequence or priority.

[0094] 3) Failure to receive a reply message may be replaced by: failure to receive a reply message to the registration request message within a specified period of time.

[0095] Receiving a registration acceptance message may be replaced by: receiving an acceptance message of a registration request message within a specified time period.

[0096] The received registration rejection message may be replaced by a rejection message of the received registration request message within a specified time period.

[0097] 4) The first event includes but is not limited to at least one of the following: operating system update, modem reset such as silent reset, etc.

[0098] 5) Unavailability period can be understood as a period of time during which the network device retains the context information of the terminal device and does not perform implicit deregistration on the terminal device. The terminal device reports the unavailability period based on the triggering of the first event. The duration corresponding to the unavailability period can be understood as the duration of the first event, that is, the duration from the start of the first event to the completion of the first event. When the terminal device reports the unavailability period information to the network device, it can report a duration value, or a duration value and a start time. If the terminal device only reports a duration value, the network device will start timing immediately after receiving the unavailability period, and retain the context information of the terminal device within the corresponding duration value. If the terminal device reports a duration value and a start time, the network device will start timing at the start time and retain the context information of the terminal device within the corresponding duration value.

[0099] 6) The network device in the embodiment of the present application may be an access management network element or a mobility management network element, for example, an AMF network element.

[0100] Figure 2 A flow chart of a communication method provided in an embodiment of the present application.

[0101] Step 201: The terminal device sends a registration request message, and correspondingly, the network device receives the registration request message.

[0102] The registration request message is used to provide the unreachable time information of the first event to the network.

[0103] Step 202: Determine various situations, such as whether a registration acceptance message is received, whether a registration rejection message is received, and whether a preset time or a first preset duration has been reached.

[0104] If no reply message is received or a registration rejection message is received, go to step 201.

[0105] If the registration acceptance message is received, go to step 203. Alternatively, after receiving the registration acceptance message, wait until a preset time or a first preset time length is reached and then go to step 203.

[0106] If the preset time or the first preset time duration is reached, go to step 203 .

[0107] Step 203: Execute the first event.

[0108] After not receiving the reply message, the terminal device resends the registration request message. This process can be understood as retransmitting the registration request message, and the resent registration request message can be understood as a retransmission message of the registration request message.

[0109] The registration rejection message includes the reason value of the registration rejection, which can make the terminal device enter the registration state, which includes the registration update attempt state or the registration PLMN search state. After receiving the registration rejection message, the terminal device can select the PLMN or cell according to the reason value and resend the registration request message. The resent registration request message can be understood as a retransmission message of the registration request message.

[0110] In an optional example, the registration request message includes the value of a non-access stratum (NAS) counter. Each time the terminal device sends a registration request message, the value of the NAS counter is increased by 1, that is, in two consecutive registration request messages sent by the terminal device, the value of the counter in the latter registration request message is 1 greater than the value of the counter in the previous registration request message. When the maximum value of the NAS counter is reached, the NAS counter starts counting from 0 or 1 again. The maximum value of the NAS counter is related to the number of bits occupied by the value of the NAS counter in the registration request message. For example, when the value of the NAS counter occupies 3 bits in the registration request message, the maximum value of the NAS counter is 7, because the binary number 111 is converted to 7 in decimal.

[0111] The preset time is the start point of the unavailability period.

[0112] If the unreachable time information carried in the registration request message includes a duration value but does not include a start time, the start of unavailability period is the time when the registration request message is first sent; if the unreachable time information includes a duration value and a start time, the start of unavailability period is the start time in the unreachable time information.

[0113] The first preset duration is the duration of the registration attempt. For example, the first preset duration is 20 minutes, 30 minutes, 1 hour, etc. The first preset duration may be set when the registration request message is sent for the first time, or when it is determined that there is a first event that needs to be executed.

[0114] In one example, the start time of the first preset duration is related to the time when the registration request message is sent for the first time. For example, the start time of the first preset duration is the first time when the registration request message is sent for the first time.

[0115] In another example, the start time of the first preset duration is related to the time when the registration request message is sent for the first time and it is determined that no reply message is received or a registration rejection message is received. For example, the start time of the first preset duration is the second time when the registration request message is sent for the first time and it is determined that the registration fails. Alternatively, the start time of the first preset duration is any time between the first time and the second time.

[0116] The process of the terminal device repeatedly sending the registration request message can be understood as a process of attempting to register. That is, before the preset time or the first preset duration is reached, the terminal device keeps trying to register, and when the preset time or the first preset duration is reached or the registration acceptance message is received, the terminal device stops trying to register. The terminal device sets the time to stop trying to register or sets the duration of trying to register to avoid delaying the execution of the first event by constantly trying to register.

[0117] Further optionally, after step 203, that is, after the first event is executed, the terminal device may send a registration request message to the network device. Optionally, the registration request message includes the type of registration, and the registration type is an initial registration type or a mobile registration type. If the first context information is saved in the terminal device after the first event is executed, the terminal device may ignore the first context information saved previously, execute the initial registration process, and renegotiate the context information with the network device; the terminal device may also execute the mobile registration process and reuse the first context information saved previously. If the first context information is not saved in the terminal device after the first event is executed, the terminal device executes the initial registration process and negotiates the context information with the network device.

[0118] Optional, in Figure 2 In the example, the terminal device is in the registration state throughout the process. For example, before sending the registration request message for the first time, the terminal device is in the registration state; when sending the registration request message for the second time, the third time, etc., the terminal device is also in the registration state; when the preset time or the first preset duration is reached, the terminal device is still in the registration state.

[0119] The following introduces multiple possible implementations of storing the first context information on the terminal device:

[0120] First of all, it should be explained that the function of the first storage space is that the data in the first storage space will not be lost when the device is shut down or the first event is executed. Exemplarily, the first storage space is a storage space of a non-volatile memory NV or a global user identity card USIM. The first context information is used for mobile management and / or session management. Exemplarily, the first context information includes MM context information and / or SM context information. The registration state may be an attempted registration update state or a registered PLMN search state. In an optional example, the 5GMM context includes the value of a registration attempt counter, and each time a registration request message is sent and no reply message is received, the value of the counter is increased by 1. Upon receiving a registration rejection message or a registration acceptance message, the counter is cleared to 0 and then restarts counting. When the value of the counter reaches the maximum value, the counter is cleared to 0 and then restarts counting.

[0121] A possible implementation method a1:

[0122] When the preset time is reached or when the first preset duration is reached, if no reply message is received for the last registration request message sent or a registration rejection message is received, the terminal device remains in the registered state and the first context information can be stored in the first storage space.

[0123] Before the terminal device sends a registration request message for the first time, in the registration state, the context information of the terminal device is maintained in the network device. After the terminal device sends a registration request message for the first time or multiple times thereafter, if the network link is not good and the network device does not receive the registration request message, the network device will still maintain the context information of the terminal device. If the network device receives a registration request message and refuses to register, but the reason value for the refusal causes the terminal device to remain in the registration state instead of entering the deregistration state, the network device will still maintain the context information of the terminal device. The network device maintains the context for a long time, generally until the execution of the first event is completed. Therefore, before the first event is executed, the terminal device stores the first context information in the first storage space, which will not be deleted when the first event is executed, so that the previously negotiated context can be reused after the first event is executed, without renegotiating with the network, which can save signaling overhead, speed up the business process, and will not interrupt the session or business.

[0124] Further optionally, the registration attempt counter in the first context information in the first storage space is reset to 0. The terminal device resets the registration attempt counter to 0, which can provide more opportunities for registration attempts. For example, a possible implementation of registration attempts is: multiple different time intervals are set in the terminal device, such as 30s, 2 minutes, 5 minutes, etc., and the upper limit of the registration attempt counter is 5. If the current registration attempt counter is 4, there is only one opportunity to attempt registration for each time interval, that is, after the terminal device attempts to register once with a time interval of 30s, if the registration fails, it will wait for 2 minutes before attempting to register again. If the registration still fails, it will wait for another 5 minutes before attempting to register again. If the registration attempt counter is reset to 0, there are 5 opportunities to attempt registration for each time interval, so more opportunities can be provided for registration attempts.

[0125] The terminal device may first reset the registration attempt counter to 0, and then store the first context information including the registration attempt counter reset to 0 in the first storage space; or the terminal device may first store the first context information in the first storage space, and then reset the registration attempt counter in the first context information in the first storage space to 0.

[0126] If the terminal device does not receive the reply message, the 5GMM status contained in the MM context is: 5GMM-REGISTERED.ATTEMPTING-REGISTRATION-UPDATE and other 5GMM registration sub-states. If the MM context contains a registration attempt counter, the registration attempt counter is set to 0.

[0127] If the terminal device receives some reason value for rejecting registration, the MM context contains 5GMM status such as 5GMM-REGISTERED.ATTENDED REGISTRATION UPDATE or 5GMM-REGISTERED.PLMN-SEARCH. If the MM context contains registration attempt counter, the registration attempt counter is set to 0.

[0128] A possible implementation method b1:

[0129] When the preset time is reached or when the first preset duration is reached, if no reply message is received for the last registration request message sent or a registration rejection message is received, the terminal device remains in the registered state and can determine whether to store the first context information in the first storage space based on the first value and the second value.

[0130] The first value is used to indicate the remaining duration of the deregistration timer, and the second value is the duration of the first event.

[0131] If the first value is greater than or equal to the second value, the first context information is stored in the first storage space; if the first value is less than the second value, the first context information is not stored in the first storage space. Alternatively, if the first value is greater than the second value, the first context information is stored in the first storage space; if the first value is less than or equal to the second value, the first context information is not stored in the first storage space.

[0132] The following are several possible examples of determining the first value:

[0133] If a registration rejection message is received for the last registration request message sent, the first value is the maximum value of the deregistration timer. When the network device sends the registration rejection message, the deregistration timer is started, ignoring the transmission delay. When the terminal device receives the registration rejection message, the remaining duration of the deregistration timer is the maximum value Tmax of the deregistration timer, that is, the first value Tmax.

[0134] If no reply message is received for the last registration request message sent, the first value is determined based on the maximum value Tmax of the de-registration timer, the time when the first event starts to execute, and the time when the last reply message was received; wherein, the last reply message received is a registration acceptance message received before the first sending of the registration request message, or a registration rejection message received after the first sending of the registration request message.

[0135] The time when the first event starts to be executed may be determined based on the start of the unavailability period or the first preset duration introduced in step 202 .

[0136] like Figure 3 As shown, the time when the terminal device first sends a registration request message is t1, the time when the first event starts to execute is t2, and the time when the reply message is last received is t3. (a) introduces that the last reply message received is the registration rejection message received after the registration request message is first sent, and (b) introduces that the last reply message received is the registration acceptance message received before the registration request message is first sent. When the network device sends a registration rejection message or a registration acceptance message, it starts the deregistration timer and ignores the transmission delay. When the terminal device receives a registration rejection message or a registration acceptance message, the remaining duration of the deregistration timer is the maximum value of the deregistration timer. After a period of time, the terminal device starts to execute the first event. At this time, the remaining duration of the deregistration timer is: the maximum value of the deregistration timer-(the time when the first event starts to execute t2-the time when the reply message is last received t3), that is, the first value is Tmax-(t2-t3).

[0137] When the network device sends a registration rejection message or a registration acceptance message to the terminal device, the network device starts a deregistration timer and counts down. When the remaining time of the deregistration timer is 0, the network device implicitly deregisters the terminal device and no longer maintains the context of the terminal device.

[0138] After receiving a registration rejection message or a registration acceptance message, if the terminal device sends a registration request message to the network device again before the remaining duration of the deregistration timer reaches 0, the network device can determine that the terminal device is online by receiving the registration request message, and will not implicitly deregister the terminal device, and will still maintain the context of the terminal device.

[0139] When the terminal device receives the registration rejection message or the registration acceptance message, it starts the periodic registration update timer T3512. The maximum value of the deregistration timer of the network device and the periodic registration update timer T3512 of the terminal device is the same or almost the same, for example, both are 54 minutes, or the deregistration timer of the network device is a few minutes longer than the maximum value of T3512, for example, 4 minutes longer.

[0140] In this example, if the remaining duration of the deregistration timer is greater than the duration of the first event, the network device also maintains the context of the terminal device when the first event is completed. The terminal device can send a registration request message to the network device when the first event is completed. The network device does not perform implicit deregistration on the terminal device after receiving the registration request message of the terminal device, and the network device continues to maintain the context information of the terminal device. Therefore, the terminal device stores the first context information in the first storage space. After the first event is completed, the previously negotiated context can be reused without renegotiating with the network, which can save signaling overhead, speed up business processes, and will not interrupt sessions or services. If the remaining duration of the deregistration timer is less than the duration of the first event, the network device has performed deregistration when the first event is completed, and does not maintain the context of the terminal device. The terminal device does not need to store the first context information in the first storage space, which can save storage space for the terminal device.

[0141] A possible implementation method c1:

[0142] When the preset time is reached or when the first preset duration is reached, if the terminal device has not received a reply message for the last registration request message sent or has received a registration rejection message, the terminal device remains in the registered state and can store the first part of the information in the first context information in the first storage space. The first part of the information is used for security verification.

[0143] The first part of information includes the first part of information used for security verification, and also includes the second part of information other than that used for security verification. The terminal device will not store the second part of information in the first storage space, so as to avoid wasting storage resources. The first part of information includes but is not limited to the currently defined MM contexts such as the Globally Unique Temporary UE Identity (GUTI) and security context, which are used to reuse the previously negotiated security context after the first event is completed to speed up the registration process.

[0144] In the mode c1, when the terminal device executes the first event, the terminal device may enter a deregistration process.

[0145] A possible implementation method d1:

[0146] The terminal device receives the registration acceptance message, remains in the registration state, and stores the first context information in the first storage space. Regardless of whether the registration acceptance message is received for a registration request message sent for the first time, or the registration acceptance message is received for a registration request message not sent for the first time, the first context information can be stored in the first storage space as long as the registration acceptance message is received.

[0147] like Figure 4 As shown, combined Figure 2 As well as implementations a1 and d1, a communication method is introduced. In the method, the terminal device is a UE, the network device is an AMF network element, the first event is an OS update or a modem reset, and the first context information is MM and SM context information.

[0148] Step 400: The UE is in a registered state.

[0149] Step 401: UE prepares for OS update or modem reset.

[0150] Step 402: The UE determines that the MM and SM context information can be stored in the first storage space.

[0151] For example, it is determined that the first storage space has remaining storage resources to store the MM and SM context information.

[0152] Step 403: The UE sends a registration request message, and the AMF network element receives the registration request message accordingly. The registration request message carries unreachable time information.

[0153] Step 404: Determine various situations, for example, whether a registration acceptance message is received, whether a registration rejection message is received, whether a preset time or a first preset duration is reached.

[0154] If no reply message is received or a registration rejection message is received, go to step 403.

[0155] If the starting point of the unreachable time or the first preset duration is reached, go to step 405a and step 405b.

[0156] If a registration acceptance message is received, go to step 406.

[0157] Step 405a: The UE does not receive a reply message for the last registration request message sent, and remains in the registered state, stores the SM and MM context information in the first storage space, and sets the registration attempt counter to 0.

[0158] The 5GMM status included in the MM context is: 5GMM-REGISTERED.ATTEMPTING-REGISTRATION-UPDATE and other 5GMM registration sub-states. If the MM context includes a registration attempt counter, the registration attempt counter is set to 0.

[0159] Step 407 is performed after step 405a.

[0160] Step 405b: The UE receives a registration rejection message including some reason values ​​for the last sent registration request message, remains in the registered state, stores the SM and MM context information in the first storage space, and sets the registration attempt counter to 0.

[0161] The MM context includes 5GMM status such as 5GMM-REGISTERED.ATTENDED REGISTRATION UPDATE or 5GMM-REGISTERED.PLMN-SEARCH. If the MM context includes a registrationattempt counter, the registrationattempt counter is set to 0.

[0162] Step 407 is performed after step 405b.

[0163] Step 406: The UE receives the registration acceptance message, remains in the registration state, and stores the SM and MM context information in the first storage space.

[0164] After step 406 , step 407 is executed.

[0165] Step 407: The UE performs an OS update or a modem reset, and after the OS update or the modem reset, performs an initial registration or a mobile registration.

[0166] like Figure 5 As shown, combined Figure 2 As well as implementations b1 and d1, a communication method is introduced. In the method, the terminal device is a UE, the network device is an AMF network element, the first event is an OS update or a modem reset, and the first context information is MM and SM context information.

[0167] Step 500 to step 503 may refer to step 400 to step 403 and will not be repeated here.

[0168] Step 504: Determine various situations, for example, whether a registration acceptance message is received, whether a registration rejection message is received, whether a preset time or a first preset duration is reached.

[0169] If no reply message is received or a registration rejection message is received, go to step 503.

[0170] If the starting point of the unreachable time or the first preset duration is reached, go to step 505 .

[0171] If a registration acceptance message is received, go to step 506.

[0172] Step 505: The UE does not receive a reply message or receives a registration rejection message for the last registration request message sent, remains in the registration state, and determines whether to store the first context information in the first storage space based on the first value and the second value.

[0173] After step 505 , step 507 is executed.

[0174] Step 506: The UE receives the registration acceptance message, remains in the registration state, and stores the SM and MM context information in the first storage space.

[0175] Step 507 is executed after step 506 .

[0176] Step 507: The UE performs OS update or modem reset, and after the OS update or modem reset, performs initial registration or mobile registration.

[0177] like Figure 6 As shown, combined Figure 2 As well as implementations c1 and d1, a communication method is introduced. In the method, the terminal device is UE, the network device is AMF network element, the first event is OS update or modem reset, and the first context information is MM and SM context information.

[0178] Step 600 to step 603 may refer to step 400 to step 403 and will not be repeated here.

[0179] Step 604: Determine various situations, for example, whether a registration acceptance message is received, whether a registration rejection message is received, whether a preset time or a first preset duration is reached.

[0180] If no reply message is received or a registration rejection message is received, go to step 603.

[0181] If the starting point of the unreachable time or the first preset duration is reached, go to step 605 .

[0182] If a registration acceptance message is received, go to step 606.

[0183] Step 605: If the UE does not receive a reply message or receives a registration rejection message for the last registration request message sent, the UE remains in the registered state and stores the currently defined MM contexts such as the GUTI and security context in the first storage space.

[0184] After step 605 , step 607 is executed.

[0185] Step 606: The UE receives the registration acceptance message, remains in the registration state, and stores the SM and MM context information in the first storage space.

[0186] Step 607: The UE performs OS update or modem reset, and after the OS update or modem reset, performs initial registration or mobile registration.

[0187] The implementations a1, b1, and c1 in the previous section respectively introduce the ways in which the terminal device stores context information. These implementations can be used with Figure 2 That is, when the preset time is reached or when the first preset time is reached, if the terminal device still does not receive a reply message or receives a registration rejection message, the above-mentioned implementation methods a1, b1 and c1 are used for storage, and these implementation methods can also be used with Figure 2 The following are some possible implementation methods:

[0188] Method a2: The terminal device sends a registration request message, which is used to provide the unreachable time information of the first event to the network; if no reply message is received or a registration rejection message is received, it remains in the registered state and stores the first context information in the first storage space; then executes the first event.

[0189] Method b2: The terminal device sends a registration request message, and the registration request message is used to provide the unreachable time information of the first event to the network; if no reply message is received or a registration rejection message is received, it remains in the registered state, and determines whether to store the first context information in the first storage space based on the first value and the second value; wherein the first value is used to indicate the remaining duration of the deregistration timer, and the second value is the duration of the first event; and then executes the first event.

[0190] Mode c2: The terminal device sends a registration request message, the registration request message is used to provide the network with the unreachable time information of the first event; if no reply message is received or a registration rejection message is received, the terminal device remains in the registration state, stores the first part of the first context information in the first storage space, and then executes the first event. Further optionally, when executing the first event, the terminal device enters the deregistration state.

[0191] Methods a2, b2 and c2 define that the first event is to be executed after sending the registration request message. The registration request message in methods a2, b2 and c2 may be a message that reaches Figure 2 The last registration request message sent before the preset time or the first preset duration in step 202 may also be a registration request message sent based on other trigger conditions or other scenarios. For other technical details of methods a2, b2, and c2, refer to methods a1, b1, and c1, and will not be repeated.

[0192] It is understandable that, in order to implement the functions in the above embodiments, the terminal device and the network device include hardware structures and / or software modules corresponding to the execution of each function. Those skilled in the art should easily realize that, in combination with the units and method steps of each example described in the embodiments disclosed in this application, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in the form of hardware or computer software driving hardware depends on the specific application scenario and design constraints of the technical solution.

[0193] Figure 7 and Figure 8 The schematic diagram of the structure of possible communication devices provided by the embodiments of the present application. These communication devices can be used to implement the functions of the network device or terminal device in the above method embodiments, and thus can also achieve the beneficial effects possessed by the above method embodiments.

[0194] like Figure 7 As shown, the communication device 700 includes a processing unit 710 and a transceiver unit 720 .

[0195] For example, the communication device 700 is used to implement the above Figure 2 , Figure 4 , Figure 5 , Figure 6 The functions of the terminal device or UE in the method embodiment shown. The transceiver unit 720 can perform the receiving action and the sending action performed by the terminal device or UE in the above method embodiment. The processing unit 710 can perform other actions except the sending action and the receiving action in the actions performed by the terminal device or UE in the above method embodiment.

[0196] In a possible implementation, the transceiver unit 720 is used to send a registration request message, where the registration request message is used to provide unreachable time information of the first event to the network.

[0197] In a possible implementation, the processing unit 710 is used to determine whether a preset time is reached, and when the preset time is reached, execute the first event; wherein the preset time is the starting point of the unreachable time.

[0198] In a possible implementation, the processing unit 710 is configured to determine whether a first preset duration has been reached, and execute the first event when the first preset duration has been reached.

[0199] In one possible implementation, the processing unit 710 is used to maintain a registered state and store first context information in a first storage space when the preset time is reached or when the first preset duration is reached, if no reply message is received for the last registration request message sent or a registration rejection message is received; wherein the first context information is used for mobile management and / or session management; when the power is turned off or the first event is executed, the data in the first storage space will not be lost.

[0200] In a possible implementation manner, the processing unit 710 is configured to reset the registration attempt counter in the first context information to 0.

[0201] In one possible implementation, the processing unit 710 is used to maintain the registration state and determine whether to store the first context information in the first storage space based on the first value and the second value when the preset time is reached or the first preset duration is reached if no reply message is received for the last registration request message sent or a registration rejection message is received; wherein the first value is used to indicate the remaining duration of the deregistration timer, and the second value is the duration of the first event.

[0202] In a possible implementation, the processing unit 710 is specifically configured to store the first context information in a first storage space if the first value is greater than or equal to the second value; and not store the first context information in the first storage space if the first value is less than the second value.

[0203] In one possible implementation, the processing unit 710 is used to maintain the registration state and store the first part of the information in the first context information in the first storage space when the preset time is reached or when the first preset duration is reached, if no reply message is received for the last registration request message sent or a registration rejection message is received; wherein the first part of the information is used for security verification.

[0204] In a possible implementation, the processing unit 710 is configured to, if receiving a registration acceptance message, remain in a registration state and store the first context information in a first storage space.

[0205] For more detailed description of the processing unit 710 and the transceiver unit 720, please refer to Figure 2 , Figure 4 , Figure 5 , Figure 6 The relevant description in the method embodiment shown is directly obtained and is not repeated here. The processing unit 710 can be implemented by a processor, and the transceiver unit 720 can be implemented by a transceiver.

[0206] like Figure 8 As shown, the communication device 800 includes a processor 810 and an interface circuit 820. The processor 810 and the interface circuit 820 are coupled to each other. It is understood that the interface circuit 820 can be a transceiver or an input-output interface. Optionally, the communication device 800 may also include a memory 830 for storing instructions executed by the processor 810 or storing input data required by the processor 810 to execute instructions or storing data generated after the processor 810 executes instructions.

[0207] For example, the communication device 800 is used to implement the above Figure 2 , Figure 4 , Figure 5 , Figure 6 The functions of the terminal device or UE in the method embodiment shown are as follows: For example, the processor 810 is used to implement the functions of the processing unit 710, and the interface circuit 820 is used to implement the functions of the transceiver unit 720.

[0208] When the above communication device is a chip applied to a network device, the network device chip implements the function of the network device in the above method embodiment. The network device chip receives information from other modules in the network device (such as a radio frequency module or an antenna), and the information is sent by the terminal device to the network device; or the network device chip sends information to other modules in the network device (such as a radio frequency module or an antenna), and the information is sent by the network device to the terminal device.

[0209] When the above-mentioned communication device is a module applied to a terminal device, the terminal device module implements the functions of the terminal device in the above-mentioned method embodiment. The terminal device module receives information from other modules in the terminal device (such as a radio frequency module or an antenna), and the information is sent by the network device to the terminal device; or, the terminal device module sends information to other modules in the terminal device (such as a radio frequency module or an antenna), and the information is sent by the terminal device to the network device. The terminal device module here can be a baseband chip of the terminal device, or it can be a DU or other module. The DU here can be a DU under the open radio access network (O-RAN) architecture.

[0210] It is understandable that the processor in the embodiments of the present application may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field programmable gate arrays (FPGA) or other programmable logic devices, transistor logic devices, hardware components or any combination thereof. The general-purpose processor may be a microprocessor or any conventional processor.

[0211] The embodiment of the present application further provides a computer-readable storage medium storing a computer program, which, when executed by a computer, enables the computer to perform the above communication method. In other words, the computer program includes instructions for implementing the above communication.

[0212] The embodiment of the present application also provides a computer program product, including: computer program code, when the computer program code is executed on a computer, the computer can execute the communication method provided above.

[0213] An embodiment of the present application also provides a communication system, which includes: a network device and a terminal device that execute the above communication method.

[0214] The method steps in the embodiments of the present application can be implemented by hardware, or by a processor executing software instructions. The software instructions can be composed of corresponding software modules, and the software modules 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 known in the art. An exemplary storage medium is coupled to the processor so that the processor can read information from the storage medium and can write information to the storage medium. Of course, the storage medium can also be a component 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. Of course, the processor and the storage medium can also be present in a base station or a terminal as discrete components.

[0215] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented by software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer programs or instructions. When the computer program or instruction is loaded and executed on a computer, the process or function described in the embodiment of the present application is executed in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, a network device, a user device or other programmable device. The computer program or instruction may 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 program or instruction may be transmitted from one website site, computer, server or data center to another website site, computer, server or data center by wired or wireless means. The computer-readable storage medium may be any available medium that a computer can access or a data storage device such as a server, data center, etc. that integrates one or more available media. The available medium may be a magnetic medium, for example, a floppy disk, a hard disk, a tape; it may also be an optical medium, for example, a digital video disc; it may also be a semiconductor medium, for example, a solid-state hard disk. The computer-readable storage medium may be a volatile or nonvolatile storage medium, or may include both volatile and nonvolatile types of storage media.

[0216] In the various embodiments of the present application, unless otherwise specified or provided for in any logical conflict, the terms and / or descriptions between the different embodiments are consistent and may be referenced to each other, and the technical features in the different embodiments may be combined to form new embodiments according to their inherent logical relationships.

[0217] In the embodiments of the present application, the number of nouns, unless otherwise specified, means "singular noun or plural noun", that is, "one or more". "At least one" means one or more, and "plural" means two or more. "And / or" describes the association relationship of associated objects, indicating that there may be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone, where A or B can be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship. For example, A / B means: A or B. "At least one of the following" or "one or more of them" and other similar expressions refer to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b, or c, or one or more of a, b, or c, means: a, b, c, a and b, a and c, b and c, or a and b and c. Each of a, b, and c can be single or multiple.

[0218] The ordinal numbers such as "first" and "second" mentioned in the embodiments of the present application are used to distinguish multiple objects, and are not used to limit the size, content, order, timing, priority or importance of multiple objects. Moreover, this name does not indicate the difference in content, sender / receiver, sending order, size, application scenario, priority or importance of the two information. In addition, the numbering of the steps in the various embodiments introduced in this application is only for distinguishing different steps, and is not used to limit the order of the steps.

Claims

1. A communication method, characterized in that: include: Sending a registration request message, where the registration request message is used to provide unreachable time information of the first event to the network; If no reply message is received or a registration rejection message is received, the registration request message is sent repeatedly until a preset time is reached; wherein the preset time is the starting point of the unreachable time; When the preset time is reached, the first event is executed.

2. A communication method, characterized in that: include: Sending a registration request message, where the registration request message is used to provide unreachable time information of the first event to the network; If no reply message is received or a registration rejection message is received, repeatedly sending the registration request message until a first preset duration is reached; When the first preset time period is reached, the first event is executed.

3. The method according to claim 2, characterized in that The start time of the first preset duration is related to the time when the registration request message is sent for the first time, or is related to the time when the registration request message is sent for the first time and it is determined that no reply message is received or a registration rejection message is received.

4. The method according to claim 2 or 3, characterized in that The first preset duration is the duration of the registration attempt.

5. The method according to any one of claims 1 to 4, characterized in that: When the preset time is reached or when the first preset duration is reached, if no reply message is received for the last sent registration request message or a registration rejection message is received, before executing the first event, the method further includes: Maintaining the registered state, and storing the first context information in the first storage space; wherein the first context information is used for mobile management and / or session management; when shutting down or executing the first event, the data in the first storage space will not be lost.

6. The method according to claim 5, characterized in that The registration attempt counter in the first context information in the first storage space is reset to 0.

7. The method according to any one of claims 1 to 4, characterized in that: When the preset time is reached or when the first preset duration is reached, if no reply message is received for the last sent registration request message or a registration rejection message is received, before executing the first event, the method further includes: Maintain a registered state, and determine whether to store first context information in a first storage space based on a first value and a second value; wherein the first value is used to indicate the remaining duration of a deregistration timer, and the second value is the duration of the first event; the first context information is used for mobile management and / or session management; when shutting down or executing the first event, the data in the first storage space will not be lost.

8. The method according to claim 7, characterized in that Determining whether to store the first context information in the first storage space based on the first value and the second value includes: If the first value is greater than or equal to the second value, storing the first context information in a first storage space; If the first value is smaller than the second value, the first context information is not stored in the first storage space.

9. The method according to claim 8, characterized in that When the preset time is reached or when the first preset duration is reached: If a registration rejection message is received for the last registration request message sent, the first value is the maximum value of the deregistration timer; If no reply message is received for the last registration request message sent, the first value is determined based on the maximum value of the de-registration timer, the time when the first event starts to execute, and the time when the last reply message was received; wherein, the last reply message received is a registration acceptance message received before the first registration request message was sent, or a registration rejection message received after the first registration request message was sent.

10. The method according to any one of claims 1 to 4, characterized in that: When the preset time is reached or when the first preset duration is reached, if no reply message is received for the last sent registration request message or a registration rejection message is received, before executing the first event, the method further includes: Maintain the registered state and store the first part of the first context information in the first storage space; wherein the first context information is used for mobile management and / or session management, and the first part of the information is used for security verification; when shutting down or executing the first event, the data in the first storage space will not be lost.

11. The method according to claim 10, characterized in that When executing the first event, it also includes: Enter the deregistration state.

12. The method according to any one of claims 1 to 11, characterized in that: The first event includes: an operating system update and / or a modem reset.

13. The method according to any one of claims 1 to 12, characterized in that: Before executing the first event, the method further includes: If a registration acceptance message is received, the registration state is maintained, and the first context information is stored in the first storage space; wherein the first context information is used for mobile management and / or session management; when shutting down or executing the first event, the data in the first storage space will not be lost.

14. A communication method, characterized in that: include: Sending a registration request message, where the registration request message is used to provide unreachable time information of the first event to the network; If no reply message is received or a registration rejection message is received, the registration state is maintained, and the first context information is stored in the first storage space; wherein the first context information is used for mobility management and / or session management; when the device is shut down or the first event is executed, the data in the first storage space will not be lost; The first event is executed.

15. The method according to claim 14, characterized in that The registration attempt counter in the first context information in the first storage space is reset to 0.

16. A communication method, characterized in that: include: Sending a registration request message, where the registration request message is used to provide unreachable time information of the first event to the network; If no reply message is received or a registration rejection message is received, the registration state is maintained, and whether to store the first context information in the first storage space is determined based on the first value and the second value; wherein the first value is used to indicate the remaining duration of the deregistration timer, and the second value is the duration of the first event; the first context information is used for mobility management and / or session management; when the device is shut down or the first event is executed, the data in the first storage space will not be lost; The first event is executed.

17. The method according to claim 16, characterized in that Determining whether to store the first context information in the first storage space based on the first value and the second value includes: If the first value is greater than or equal to the second value, storing the first context information in a first storage space; If the first value is smaller than the second value, the first context information is not stored in the first storage space.

18. The method according to claim 17, characterized in that If a registration rejection message is received, the first value is the maximum value of the deregistration timer; If no reply message is received, the first value is determined based on a maximum value of a deregistration timer, a time when the first event starts to be executed, and a time when a reply message was last received before the registration request message was sent.

19. A communication method, characterized in that: include: Sending a registration request message, where the registration request message is used to provide unreachable time information of the first event to the network; If no reply message is received or a registration rejection message is received, the registration state is maintained, and the first part of the first context information is stored in the first storage space; wherein the first context information is used for mobile management and / or session management, and the first part of the information is used for security verification; when the device is shut down or the first event is executed, the data in the first storage space will not be lost; The first event is executed.

20. The method of claim 19, wherein: When executing the first event, it also includes: Enter the deregistration state.

21. The method according to any one of claims 13 to 20, characterized in that: Before executing the first event, the method further includes: If a registration acceptance message is received, the registration state is maintained, and the first context information is stored in the first storage space; wherein the first context information is used for mobile management and / or session management; when shutting down or executing the first event, the data in the first storage space will not be lost.

22. The method according to any one of claims 13 to 21, characterized in that: The first event includes: an operating system update and / or a modem reset.

23. A communication device, characterized in that: Comprising modules for executing the method as claimed in any one of claims 1 to 22.

24. A communication device, characterized in that: comprising a processor coupled to a memory; The memory is used to store computer programs or instructions; The processor is used to execute part or all of the computer programs or instructions in the memory, and when the part or all of the computer programs or instructions are executed, it is used to implement the method according to any one of claims 1 to 22.

25. A communication device, characterized in that: including a processor and a memory; The memory is used to store computer programs or instructions; The processor is used to execute part or all of the computer programs or instructions in the memory, and when the part or all of the computer programs or instructions are executed, it is used to implement the method according to any one of claims 1 to 22.

26. A communication device, characterized in that: It includes a processor and an interface circuit, wherein the interface circuit is used to receive signals from other communication devices outside the communication device and transmit them to the processor or send signals from the processor to other communication devices outside the communication device, and the processor is used to implement the method as described in any one of claims 1-22 through a logic circuit or executing code instructions.

27. A communication system, characterized in that: The communication system comprises: a terminal device for executing the method according to any one of claims 1 to 22 and a network device for interacting with the terminal device.

28. A computer-readable storage medium, characterized in that: The storage medium stores a computer program or an instruction, and when the computer program or the instruction is executed by the communication device, the method according to any one of claims 1 to 22 is implemented.

29. A computer program product, characterized in that The computer program product comprises: computer instructions, and when the computer instructions are executed on a computer, the method according to any one of claims 1 to 22 is implemented.

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