Communication method and terminal equipment

Abstract

The embodiment of the invention provides a communication method and terminal equipment, and relates to the technical field of terminal equipment. The method aims at optimizing the condition that the network does not respond when the terminal equipment initiates the protocol data unit (PDU) session establishment request of the data service to the network, effectively reducing the unnecessary waiting time of a user, realizing the efficient access of the data service, and improving the use experience of the user. The method comprises the following steps: a terminal device is attached to a first network device of a first cell; the terminal device sends a first PDU session establishment request to the first network device; when the terminal device does not receive a first response message of the first PDU session establishment request within a first duration, the terminal device is reattached to the first network device; then, the terminal device sends a second PDU session establishment request to the first network device; and when the terminal device does not receive a second response message of the second PDU session establishment request within a second duration, the terminal device disables the first cell to avoid further waiting.

Description

Technical Field

[0001] This application relates to the field of terminal device technology, and in particular to a communication method and a terminal device. Background Technology

[0002] Currently, when a terminal device initiates a Protocol Data Unit (PDU) session establishment request to the network for a data service, a situation may arise where the network does not respond. When a terminal device initiates a PDU session establishment request but the network does not respond, the terminal device typically waits for a preset time and then re-initiates the request. If the network still does not respond upon re-initiating the request, the terminal device will wait for the preset time again and retry, repeating this process multiple times. Therefore, in this situation, the process is time-consuming, causing prolonged lag for users accessing data services and impacting their user experience. Summary of the Invention

[0003] This application provides a communication method and a terminal device that can optimize the problem of the terminal device initiating a PDU session establishment request for data services but the network not responding, thereby minimizing unnecessary waiting time for users, efficiently enabling access to data services, and improving the user experience.

[0004] In a first aspect, embodiments of this application provide a communication method, including:

[0005] The terminal device attaches to the first network device in the first cell;

[0006] The terminal device sends a first protocol data unit (PDU) session establishment request to the first network device;

[0007] If the terminal device does not receive the first response message for the first PDU session establishment request within the first time period, the terminal device reattaches to the first network device.

[0008] The terminal device sends a second PDU session establishment request to the first network device;

[0009] If the terminal device does not receive a second response message for the second PDU session establishment request within the second time period, the terminal device disables the first cell.

[0010] In the above scheme, since the terminal device chooses to reattach to the first network device after not receiving the first response message for the first PDU session establishment request within the first time period, instead of repeatedly waiting as in the prior art, it can effectively reduce the abnormal waiting time caused by the network not responding to the PDU session establishment request. Furthermore, when the terminal device does not receive the second response message for the second PDU session establishment request within the second time period, it will disable the first cell; therefore, it can promptly disable the abnormal cell, enabling the terminal device to quickly attach to other cells, thereby reducing abnormal waiting time and improving the success rate of PDU session establishment.

[0011] In conjunction with the first aspect, in some implementations of the first aspect, after the terminal device attaches to the first network device of the first cell, it further includes:

[0012] The terminal device sends a third PDU session establishment request to the first network device;

[0013] If the terminal device does not receive the third response message for the third PDU session establishment request within the third time period, the terminal device reattaches to the second network device of the second cell. The second cell is different from the first cell, and both the second network device and the first network device belong to the first network.

[0014] The terminal device sends a fourth PDU session establishment request to the second network device;

[0015] If the terminal device does not receive the fourth response message for the fourth PDU session establishment request within the fourth time period, the terminal device disables the SA capability.

[0016] In the above scheme, if the terminal device does not receive the fourth response message for the fourth PDU session establishment request within the fourth time period, the terminal device will disable its SA capability. In other words, if the terminal device attaches to different cells twice and does not receive a response message for the PDU session establishment request in either case, it indicates that both cells near the terminal device have problems, which may be a network-wide issue rather than a problem with a single cell. Therefore, disabling the SA capability by the terminal device effectively reduces abnormal waiting time by disabling the problematic network and avoiding repeated waiting in that network.

[0017] In conjunction with the first aspect, some implementations of the first aspect further include, after the terminal device disables the first cell, the following:

[0018] The terminal device reattaches to the third network device in the third cell, which is different from the first cell;

[0019] The terminal device sends a fifth PDU session establishment request to the third network device;

[0020] If the terminal device does not receive the fifth response message for the fifth PDU session establishment request within the seventh time period, the terminal device disables the SA capability.

[0021] In the above scheme, if the terminal device does not receive the fifth response message for the fifth PDU session establishment request within the seventh time period, the terminal device will disable its SA capability. In other words, after the terminal device disables the first cell, even if the network device reattaches to a different cell, it still will not receive the response message for the PDU session establishment request. This indicates that both cells near the terminal device have problems, which may be a network-wide issue rather than a problem with a single cell. Therefore, disabling the SA capability by the terminal device, by disabling the problematic network, avoids repeated waiting in that network, thereby effectively reducing abnormal waiting time.

[0022] In conjunction with the first aspect, some implementations of the first aspect also include the following methods:

[0023] Once the terminal device receives the fifth response message within the seventh time period, the terminal device establishes a PDU session.

[0024] In the above scheme, when the terminal device receives the fifth response message within the seventh time period, the terminal device establishes a PDU session. That is to say, if the terminal device can successfully receive the response message of the PDU session establishment request, it can establish a PDU session in a timely manner. Through the PDU session, the network can effectively manage and allocate resources, thereby enabling users to better use data services and improve user experience.

[0025] In conjunction with the first aspect, some implementations of the first aspect, after the terminal device disables the SA capability, also include:

[0026] The terminal device attaches to a third network device in the second network, which is different from the first network.

[0027] In the above scheme, after the terminal device disables the SA capability, the terminal device attaches to the third network device of the second network, which is different from the first network. In other words, after the terminal device disables the SA capability, it can still attach to other networks in a timely manner. This can avoid repeated waiting in the problematic network, reduce abnormal waiting time, and continue data services in other networks, so as to minimize the impact on users.

[0028] In conjunction with the first aspect, in some implementations of the first aspect, after the terminal device reattaches to the first network device, the following is also included:

[0029] In response to the user's first operation, the terminal device sends a sixth PDU session establishment request to the first network device, and the terminal device does not receive a sixth response message for the sixth PDU session establishment request within a fifth time period;

[0030] In response to the terminal device detecting the first operation, the terminal device determines that it has not received the sixth response message for the sixth PDU session establishment request within the fifth time period;

[0031] Terminal devices can disable the first cell, including:

[0032] In response to the sixth response message indicating that the terminal device has not received a sixth PDU session establishment request within the fifth time period, the terminal device disables the first cell.

[0033] In the above scheme, in response to the user's first operation, the terminal device can initiate a PDU session establishment request. This means that, in addition to handling PDU session establishment anomalies, the terminal device can also execute corresponding actions based on the user's input. This demonstrates that the terminal device can respect the user's autonomy and control, rather than forcibly implementing an optimized scheme. Furthermore, since the terminal device sends a sixth PDU session establishment request to the first network device in response to the user's first operation, and the terminal device does not receive a sixth response message for the sixth PDU session establishment request within the fifth time interval, it indicates that the user-triggered sixth PDU session establishment request also did not receive a response message from the first cell. In other words, this cell is likely problematic. Subsequently, in response to confirming that the terminal device has not received a sixth response message for the sixth PDU session establishment request within the fifth time interval, the terminal device disables the first cell. This indicates that the cell has failed to respond to PDU session establishment requests twice consecutively. The timely disabling of the abnormal cell allows the terminal device to attach to other cells promptly, thereby reducing the anomaly waiting time.

[0034] In conjunction with the first aspect, in some implementations of the first aspect, the first operation includes one or more of the following operations: turning off the flight mode after turning on the flight mode of the terminal device, removing the USIM card and inserting it back in, removing the SIM card and inserting it back in, turning off the terminal device and turning it on, switching the USIM card to a different USIM card, switching the SIM card to a different SIM card, turning off the 5G switch and turning it on.

[0035] In the above scheme, the user's first action can be any operation that causes the terminal device to reattach.

[0036] In conjunction with the first aspect, in some implementations of the first aspect, before the terminal device reattaches to the first network device, the following steps are also included:

[0037] The terminal device connects to the first incoming call;

[0038] The terminal device terminates the first call six hours after it connects to the first call.

[0039] In response to the terminal device ending the first incoming call, the terminal device reattaches to the first network device.

[0040] In conjunction with the first aspect, in some implementations of the first aspect, before the terminal device reattaches to the first network device, the following steps are also included:

[0041] The terminal device connects to the first incoming call;

[0042] The terminal device terminates the first call six hours after it connects to the first call.

[0043] The terminal device does not send an Attach request to the first network device before the terminal device ends the first incoming call.

[0044] In the above scheme, the terminal device reattaches to the first network device in response to the terminal device ending the first incoming call; that is, the terminal device will not reattach if it does not end the first incoming call. During a call, call quality is often more important to the user, while the activation of data services can be postponed. In this way, the call quality of the terminal device can be guaranteed as much as possible, without being affected by reattaching.

[0045] In conjunction with the first aspect, in some implementations of the first aspect, before the terminal device attaches to the first network device of the first cell, the following is also included:

[0046] The terminal device sends M PDU session establishment requests to the first network, where M is a positive integer.

[0047] In the above scheme, the terminal device does not necessarily start the overall process when it sends the first PDU session establishment request to the first network. It can start the overall process after M times. This can provide a more conservative way of handling exceptions, giving the terminal device a normal waiting opportunity first, and then implementing a more powerful exception handling method.

[0048] In conjunction with the first aspect, in some implementations of the first aspect, after the terminal device does not receive the first response message for the first PDU session establishment request within a first time period, the method further includes:

[0049] At the first moment, the terminal device records the cell where the terminal device is camped at the first moment;

[0050] If the terminal device does not receive a second response message for the second PDU session establishment request within the second time period, the following is also included:

[0051] At the second moment, the terminal device records the cell where the terminal device is camped at the second moment, which is later than the first moment.

[0052] Disabling the first cell on terminal devices also includes:

[0053] If the cell in which the terminal device camps at the first moment is the same as the cell in which the terminal device camps at the second moment, the terminal device disables the first cell.

[0054] In the above scheme, the terminal device records the cell information it is camped on when it does not receive a response message for a PDU session establishment request. Then, by comparing the two recorded cell information entries, it determines whether the cell is abnormal. If the cell entries are identical, the abnormal cell is promptly disabled. This allows the terminal device to attach to other cells quickly, reducing abnormal waiting time and improving the success rate of PDU session establishment.

[0055] In conjunction with the first aspect, in certain implementations of the first aspect, the terminal device disables the first cell, including:

[0056] The terminal device does not send an Attach request to the first cell within the third time period.

[0057] In the above scheme, the terminal device does not send an Attach request to the first cell for a certain period of time, which allows the terminal device to try to attach to other cells in the short term, providing more possibilities and improving the success rate of the terminal device establishing a PDU session.

[0058] In conjunction with the first aspect, in certain implementations of the first aspect, the terminal device disables SA capability, including:

[0059] The terminal device does not send an Attach request to the first network;

[0060] The terminal device sends an Attach request to a second network, which is different from the first network.

[0061] In the above solution, after the terminal device disables the access capability of the problematic network, it can send an Attach request to other networks to try to activate data services on other networks and ensure the user's data service experience as much as possible.

[0062] In conjunction with the first aspect, in some implementations of the first aspect, the PDU session establishment request includes a PDUSESSION ESTABLISHMENT REQUEST message.

[0063] In conjunction with the first aspect, in some implementations of the first aspect, the response message for the PDU session establishment request includes either the PDU SESSION ESTABLISHMENT ACCEPT message or the PDU SESSION ESTABLISHMENT REJECT message.

[0064] In the above scheme, the terminal device is not limited to receiving response information including the PDU SESSION ESTABLISHMENT ACCEPT message indicating successful PDU session establishment. Even receiving response information including the PDU SESSION ESTABLISHMENT REJECT message indicating PDU session establishment failure can be considered as receiving a response message. Because response information including the PDU SESSION ESTABLISHMENT REJECT message can clearly identify the abnormal situation on the network side, the terminal device can also initiate relevant processing procedures. Through this scheme, the terminal device can handle more different types of abnormal situations.

[0065] In conjunction with the first aspect, in some implementations of the first aspect, the first network is a fifth-generation standalone 5G SA network, and the second network is a long-term evolution LTE network.

[0066] In the above scheme, terminal devices can switch from 5G SA network to LTE network under certain circumstances. By reducing the network standard, they can escape to other networks in a timely manner and ensure the operation of data services.

[0067] Secondly, embodiments of this application provide a terminal device, which includes a memory and a processor coupled to the memory; the memory stores a computer program, and when the processor executes the computer program, it causes the terminal device to implement the method described in any one of the first aspects.

[0068] Thirdly, embodiments of this application provide a computer-readable storage medium storing a computer program or computer instructions, which are executed by a processor to implement the method described in any of the first aspects above.

[0069] Fourthly, embodiments of this application provide a computer program product, which, when executed by a processor, implements the method described in any of the first aspects above.

[0070] Fifthly, this application provides a communication apparatus for performing the method in the first aspect or any possible implementation thereof. Specifically, the apparatus may include modules for performing the method in the first aspect or any possible implementation thereof.

[0071] In a sixth aspect, this application provides a communication device, the device including a processor coupled to a memory for storing computer programs or instructions, and the processor for executing the computer programs or instructions stored in the memory, such that the method in the first aspect is executed.

[0072] For example, a processor is used to execute computer programs or instructions stored in memory, causing the device to perform the method in the first aspect.

[0073] Optionally, the device may include one or more processors.

[0074] Optionally, the device may also include a memory coupled to the processor.

[0075] Optionally, the device may include one or more memories.

[0076] Alternatively, the memory can be integrated with the processor or set up separately.

[0077] Optionally, the device may also include a transceiver.

[0078] In a seventh aspect, a computer-readable storage medium is provided having a computer program (also referred to as instructions or code) stored thereon for implementing the method of the first aspect.

[0079] For example, when the computer program is executed by a computer, it enables the computer to perform the methods in the first aspect. The computer can be a communication device.

[0080] Eighthly, this application provides a chip including a processor. The processor is configured to read and execute a computer program stored in a memory to perform the methods in the first aspect and any possible implementation thereof.

[0081] Optionally, the chip further includes a memory, which is connected to the processor via a circuit or wire.

[0082] Alternatively, the chip may further include a communication interface.

[0083] Ninthly, this application provides a computer program product comprising a computer program (also referred to as instructions or code), which, when executed by a computer, causes the computer to implement the method of the first aspect. The computer may be a communication device.

[0084] In a tenth aspect, embodiments of this application provide a chip system applied to a terminal device. The chip system includes one or more processors, which invoke computer instructions to cause the terminal device to execute the method described in any of the first aspects above. The processor may be a modem.

[0085] The solutions provided in the second to tenth aspects above are used to implement or cooperate with the methods provided in the first aspect above, and therefore can achieve the same or corresponding beneficial effects as the methods in the first aspect, which will not be elaborated here. Attached Figure Description

[0086] Figure 1 This is a schematic diagram of the architecture of a communication system provided in an embodiment of this application.

[0087] Figure 2 This is a schematic diagram illustrating the interaction between a terminal device and a network in a communication system, as provided in an embodiment of this application.

[0088] Figure 3 This is a schematic diagram of the hardware structure of a terminal device provided in an embodiment of this application.

[0089] Figure 4 This is a schematic diagram of the signaling interaction of the communication methods provided by related technologies.

[0090] Figure 5 This is a flowchart illustrating a communication method provided in an embodiment of this application.

[0091] Figure 6 This is a flowchart illustrating another communication method provided in an embodiment of this application.

[0092] Figure 7 This is a flowchart illustrating another communication method provided in an embodiment of this application.

[0093] Figure 8 This is a signaling interaction diagram of a communication method provided in an embodiment of this application.

[0094] Figure 9 This is a signaling interaction diagram of another communication method provided in the embodiments of this application.

[0095] Figure 10 This is a schematic block diagram of a communication device provided in an embodiment of this application.

[0096] Figure 11 This is a schematic block diagram of a communication device provided in an embodiment of this application. Detailed Implementation

[0097] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0098] The technical solutions of this application embodiment can be applied to various communication systems, such as: Global System for Mobile Communications (GSM) system, Code Division Multiple Access (CDMA) system, Wideband Code Division Multiple Access (WCDMA) system, General Packet Radio Service (GPRS), Long Term Evolution (LTE) system, LTE Frequency Division Duplex (FDD) system, LTE Time Division Duplex (TDD) system, Universal Mobile Telecommunication System (UMTS), Worldwide Interoperability for Microwave Access (WiMAX) communication system, future 5G systems, or new radio (NR), etc.

[0099] Terminal equipment, also known as terminal, user equipment (UE), mobile station (MS), mobile terminal (MT), etc., includes devices that provide voice and / or data connectivity to users. Specifically, it includes devices that provide voice connectivity, devices that provide data connectivity, or devices that provide both voice and data connectivity. For example, it may include handheld devices with wireless connectivity or processing devices connected to a wireless modem. This terminal equipment can communicate with core network equipment via radio access network (RAN) equipment, exchanging voice or data with the RAN, or interacting with the RAN to exchange voice and data. The terminal devices can include mobile phones, smart TVs, wearable devices, tablets, computers with wireless transceiver capabilities, virtual reality (VR) terminal devices, augmented reality (AR) terminal devices, wireless terminals in industrial control, wireless terminals in self-driving, wireless terminals in remote medical surgery, wireless terminals in smart grids, wireless terminals in transportation safety, wireless terminals in smart cities, wireless terminals in smart homes, wireless terminal devices, mobile terminal devices, device-to-device (D2D) communication terminal devices, vehicle-to-everything (V2X) terminal devices, machine-to-machine / machine-type communications (M2M / MTC) terminal devices, Internet of Things (IoT) terminal devices, subscriber units, and subscriber stations. Station, mobile station, remote station, access point (AP), remote terminal, access terminal, user terminal, user agent, or user device, etc.For example, this can include mobile phones (or "cellular" phones), computers with mobile terminal devices, and portable, pocket-sized, handheld, or computer-embedded mobile devices. Examples include Personal Communication Service (PCS) phones, cordless phones, Session Initiation Protocol (SIP) phones, Wireless Local Loop (WLL) stations, and Personal Digital Assistants (PDAs). It also includes limited devices, such as those with low power consumption, limited storage capacity, or limited computing power. Examples include information sensing devices such as barcode scanners, radio frequency identification (RFID), sensors, Global Positioning System (GPS), and laser scanners.

[0100] In this embodiment, the terminal device may further include a relay. Alternatively, it can be understood that anything capable of data communication with a base station can be considered a terminal device.

[0101] In this application embodiment, the device for implementing the functions of the terminal device can be the terminal device itself, or it can be a device capable of supporting the terminal device in implementing the functions, such as a chip system, which can be installed in the terminal device. In this application embodiment, the chip system can be composed of chips, or it can include chips and other discrete devices. In the technical solutions provided in this application embodiment, the terminal device is used as an example to describe the technical solutions provided in this application embodiment.

[0102] In this embodiment, the device used to implement the function of the network device can be a network device itself, or a device capable of supporting the network device in implementing that function, such as a chip system. This device can be installed within the network device. In this embodiment, taking a network device as an example, the device used to implement the function of the network device includes, but is not limited to: evolved Node B (eNB), radio network controller (RNC), Node B (NB), base station controller (BSC), base transceiver station (BTS), home evolved Node B (or home Node B (HNB), baseband unit (BBU), access point (AP), wireless relay node, wireless backhaul node, transmission point (TP), or transmission and reception point (TRP) in a wireless fidelity (WIFI) system. It can also be a fifth-generation (5G) system, such as a new radio (NR) system. A 5G base station (gNB) or transmission point (TRP or TP) in a radio (NR) system refers to one or a group of antenna panels (including multiple antenna panels) of a base station in a 5G system. Alternatively, it can be a network node constituting a gNB or transmission point, such as a baseband unit (BBU) or distributed unit (DU). A 5G base station can include various forms of macro base stations, micro base stations, relay stations, access points, etc. The name of the equipment with base station functionality may differ in systems employing different radio access technologies.

[0103] In some deployments, a gNB may include a centralized unit (CU) and a distributed unit (DU). The gNB may also include an active antenna unit (AAU). The CU implements some of the gNB's functions, and the DU implements others. For example, the CU handles non-real-time protocols and services, implementing the functions of the radio resource control (RRC) and packet data convergence protocol (PDCP) layers. The DU handles physical layer protocols and real-time services, implementing the functions of the radio link control (RLC), media access control (MAC), and physical (PHY) layers. The AAU implements some physical layer processing functions, radio frequency processing, and related functions of the active antenna. Since RRC layer information ultimately becomes PHY layer information, or is derived from PHY layer information, in this architecture, higher-layer signaling, such as RRC layer signaling, can also be considered as being sent by the DU, or by the DU+AAU. It is understood that network devices can be one or more of the following: CU nodes, DU nodes, and AAU nodes. Furthermore, a CU can be classified as a network device in the RAN, or it can be classified as a network device in the core network (CN); this application does not limit this classification.

[0104] To facilitate understanding of the embodiments of this application, some terms used in the embodiments of this application are explained below, so that those skilled in the art can understand them.

[0105] 1) Cell: also known as a cellular cell, refers to the area covered by wireless signals in mobile communications.

[0106] Mobile communication networks can adopt a cellular structure, which involves setting up multiple base stations in different locations. Each base station forms a cell, and each base station is responsible for the communication of mobile users within its cell area. For details, see... Figure 2 The diagram illustrates a communication system that may include: terminal device 10 and multiple network devices (e.g., base stations): network device 21, network device 22, and network device 23. Network device 21 corresponds to cell A, network device 22 corresponds to cell B, and network device 23 corresponds to cell C. The network coverage areas of cell A overlap to some extent with those of the adjacent cells B and C.

[0107] Cell handover is a common process in mobile communication networks to maintain continuous connectivity and quality of service for terminal devices. It occurs when a change of location occurs during communication, or when the current cell has poor signal or other abnormal conditions.

[0108] It should be noted that, Figure 1 Taking one network device corresponding to one cell as an example, in other embodiments, one network device may also correspond to multiple cells. Figure 2 The communication system shown is only one example of a communication system. In other embodiments, the communication system may include more or fewer terminal devices and network devices than shown.

[0109] 2) Protocol Data Unit (PDU) Session

[0110] In mobile communication networks, a PDU session is established to create a data transmission channel between the terminal device and the network. Once established, the terminal device can send and receive data through this connection, including various data services such as web browsing, video playback, and file downloading. A session is a connection between the terminal device and the data network used for data transmission between them. Depending on the different session requirements of various applications, a single terminal device can establish multiple PDU sessions simultaneously to transmit data from different applications.

[0111] Specifically, during the PDU session establishment process, the terminal device can send a PDU session establishment request message to the core network through the access network device, and the core network can send a PDU session establishment response message to the terminal device through the access network device.

[0112] 3) Attach

[0113] Attach refers to the process by which a terminal device establishes a connection with the network in a mobile communication network. This process is a prerequisite for the terminal device to perform data transmission and other communication operations. Attach operations typically occur when the device is first powered on, restarted, or enters a new network coverage area, but can also occur under other conditions.

[0114] Specifically, the terminal device may send an initial registration request to the network device. This initial registration request may include an Attach Request, or it may be referred to as an Attach Request message. That is, the initial registration request may be used to attach to the first or second network (first network device, second network device, or third network device) described below. The initial registration process may also include an attach process.

[0115] 4) Reattach

[0116] Reattach, also known as re-attach, refers to the process by which a terminal device re-attaches itself in a mobile communication network. This process typically occurs after a terminal device loses its connection to the network for some reason (such as network failure or signal loss) and attempts to re-establish a connection, but it can also occur under other conditions. Specifically, the reattach process includes deattach and attach. First, the terminal device performs a deattach operation, disconnecting its current network connection. After the deattach operation is complete, the terminal device can re-initiate an attach request to attempt to reconnect to the network. This process is similar to the attach process when the device first connects to the network. The reattach operation can help restore the connection between the terminal device and the network, or it can be used for switching between different networks.

[0117] See Figure 2 , Figure 2 (a) shows a schematic diagram of the architecture of a communication system according to an embodiment of this application. Figure 2 The communication system may include terminal device 10 and network 20, wherein network 20 may be a standalone (SA) network 20. It should be noted that network 20 may also be an LTE network 20, a 6G network 20, or other types of network 20; this application does not limit the specific type. For ease of description, SA network 20 will be used as an example below. SA network 20 may also be referred to as 5G network 20.

[0118] It should be noted that all terminal devices in this application can be referred to as electronic devices. Standalone (SA) is a network mode of the 5th generation (5G) mobile communication. An SA network can refer to a new radio (NR) network under the SA mode.

[0119] For example, SA network 20 may include access network equipment (e.g., gNB) and core network equipment (e.g., 5G core network equipment, denoted as 5GC), and correspondingly, SA network may be called 5G SA network. A wireless connection can be established between terminal device 10 and 5G SA network 20, and SA network can provide communication services to terminal device 10. Specifically, terminal device 10 needs to first initiate a PDU session establishment request to 5G SA network 20. Only after 5G SA network 20 sends a PDU session establishment response to terminal device 10 is the PDU session establishment between terminal device 10 and 5G SA network 20 completed. Figure 2 As shown, terminal device 10 initiates a PDU session establishment request to the 5G SA network 20. Specifically, the terminal device sends a PDU session establishment request message to a network element device (such as a RAN device, like a gNB) in the 5G SA network 20. After receiving the PDU session establishment request message, the network element device can... Figure 2 In (a), a PDU session establishment acceptance message or a PDU session establishment rejection message is sent to terminal device 10, or, as in Figure 2 In (b), no response is sent.

[0120] Optionally, if the network can meet the terminal device's request and there are no limitations or problems, the network element can send a PDU session establishment accept message to the terminal device. This message indicates that the PDU session has been successfully established, and the terminal device can begin data transmission.

[0121] For example, if a terminal device receives a PDU session establishment response after sending a PDU session establishment request to the network, it means that the terminal PDU session has been successfully established. This is a scenario where the PDU session establishment is normal.

[0122] Optionally, if the network cannot fulfill the terminal device's request (e.g., due to insufficient resources, policy restrictions, or other reasons), the network element can send a PDU session establishment rejection message to the terminal device. This message indicates that the PDU session establishment has failed, and the terminal device needs to handle the rejection situation, which may involve attempting to re-initiate the request or taking other measures.

[0123] For example, if the terminal device receives a rejection message from the SA network, this is an abnormal scenario where the PDU session establishment fails.

[0124] Optionally, in some cases, network elements may not send any response to the terminal device. This may be due to network failure, lost signaling messages, or other errors. According to the 3GPP TS24.501 protocol, in this situation, the terminal device will start a T3580 timer to wait for a network response. If the timer expires, the terminal device will retry the PDU session establishment request, up to four times.

[0125] For example, if the terminal device does not receive a response message (which can be an accept message or a reject message) within a preset time period after sending a PDU session establishment request message to the SA network, it means that the SA network failed to respond to the terminal device within the preset time period, and the terminal device will abandon this PDU session establishment request. Abandoning this PDU session establishment request means that the terminal device does not continue to wait for the SA network's response to this PDU session establishment request, but instead resends a new PDU session establishment request.

[0126] Specifically, this preset duration refers to the timer T3580 started when the PDU SESSION ESTABLISHMENT REQUEST message is sent (usually 16 seconds, but 21 or 24 seconds in special scenarios, etc.). After a maximum of 4 retries, i.e., a total of 5 attempts, if the fifth attempt times out, the terminal device will abandon the PDU session establishment request. See details for further information. Figure 4 Steps S401 to S409 will not be described in detail here.

[0127] It should be noted that after the network receives the PDU session establishment request message, the specific description of the signaling interaction between various network elements can be found in the detailed description of network registration and PDU session connection establishment in relevant technologies, which will not be repeated here.

[0128] It should be noted that, Figure 2 This illustration uses a terminal device, an access network device, and a core network device as an example. It can be understood that the embodiments of this application can be applied to a communication system including one or more access network devices, or to a communication system including one or more terminal devices. This application does not limit the application in this regard.

[0129] For ease of explanation, this application uses a mobile terminal, such as a mobile phone, as an example to describe the hardware structure of the terminal device 100. It should be noted that the terminal device 100 here can be... Figure 2 Terminal 10 in the middle. See also Figure 3For example, the terminal device 100 may include: a processor 110, an external memory interface 120, an internal memory 121, a universal serial bus (USB) interface 130, a charging management module 140, a power management module 141, a battery 142, an antenna 1, an antenna 2, a mobile communication module 150, a wireless communication module 160, an audio module 170, a sensor module 180, a button 190, a motor 191, an indicator 192, a camera 193, a display screen 194, and a subscriber identification module (SIM) card interface 195, etc.

[0130] Antenna 1 and antenna 2 are used to transmit and receive electromagnetic wave signals.

[0131] Specifically, in the various embodiments of this application, the signaling, messages, etc. sent or received by the terminal device 100 can be implemented through antenna 1 or antenna 2.

[0132] See also Figure 3 For example, mobile communication module 150 can provide wireless communication solutions including 2G / 3G / 4G / 5G for use on terminal device 100. Wireless communication module 160 can provide wireless communication solutions including wireless local area networks (WLAN) (such as wireless fidelity (Wi-Fi) networks), Bluetooth (BT), global navigation satellite system (GNSS), frequency modulation (FM), near field communication (NFC), infrared (IR), and other wireless communication technologies for use on terminal device 100.

[0133] For example, in some implementations, the antenna 1 of the terminal device 100 is coupled to the mobile communication module 150, and the antenna 2 is coupled to the wireless communication module 160, so that the terminal device 100 can communicate with the network and other devices through wireless communication technology.

[0134] See also Figure 3 For example, the audio module 170 of the terminal device 100 includes a speaker 170A, a receiver 170B, a microphone 170C, a headphone jack 170D, etc.

[0135] For example, the terminal device 100 can implement audio functions through the speaker 170A, receiver 170B, microphone 170C, headphone jack 170D, and application processor in the audio module 170.

[0136] Furthermore, regarding the sensor module 180 in the terminal device 100, in some embodiments it may include pressure sensors, gyroscope sensors, barometric pressure sensors, magnetic sensors, accelerometers, distance sensors, proximity sensors, fingerprint sensors, temperature sensors, touch sensors, ambient light sensors, bone conduction sensors, etc., which will not be listed here, and this application does not impose any limitations on them.

[0137] Furthermore, it should be noted that in some implementations, the processor 110 may include one or more processing units, such as an application processor (AP), a modem, a graphics processing unit (GPU), an image signal processor (ISP), a controller, a memory, a video codec, a digital signal processor (DSP), a baseband processor, and / or a neural network processing unit (NPU), etc.

[0138] Understandably, in a practical implementation, different processing units can be independent devices or integrated into one or more processors.

[0139] Furthermore, it should be noted that in some implementations, the controller can serve as the central nervous system and command center of the terminal device 100. In practical applications, the controller can generate operation control signals based on the instruction opcode and timing signals to control the fetching and execution of instructions.

[0140] Furthermore, it should be noted that in some implementations, the processor 110 may also include a memory for storing instructions and data. In some implementations, the memory in the processor 110 is a cache memory. This memory can store instructions or data that the processor 110 has just used or is recurring. If the processor 110 needs to use the instruction or data again, it can directly retrieve it from the memory. This avoids repeated accesses, reduces the waiting time of the processor 110, and thus improves the efficiency of the system.

[0141] Furthermore, it should be noted that in some implementations, the processor 110 may include one or more interfaces. These interfaces may include an inter-integrated circuit (I2C) interface, an inter-integrated circuit sound (I2S) interface, a pulse code modulation (PCM) interface, a universal asynchronous receiver / transmitter (UART) interface, a mobile industry processor interface (MIPI), a general-purpose input / output (GPIO) interface, a subscriber identity module (SIM) interface, and / or a universal serial bus (USB) interface, etc.

[0142] See also Figure 3 For example, the charging management module 140 is used to receive charging input from the charger. While charging the battery 142, the charging management module 140 can also supply power to the terminal device through the power management module 141.

[0143] See also Figure 3 For example, power management module 141 connects battery 142, charging management module 140, and processor 110. Power management module 141 receives input from battery 142 and / or charging management module 140 to power processor 110, internal memory 121, external memory, display 194, camera 193, and wireless communication module 160, etc. Power management module 141 can also be used to monitor parameters such as battery capacity, battery cycle count, and battery health status (leakage current, impedance). In some other implementations, power management module 141 may also be located within processor 110. In other implementations, power management module 141 and charging management module 140 may be located in the same device.

[0144] See also Figure 3 For example, the wireless communication function of terminal device 100 can be implemented through antenna 1, antenna 2, mobile communication module 150, wireless communication module 160, modem 110A, etc. Specifically, in the technical solution provided in the embodiments of this application, the processing logic after initiating a call service can be implemented by these modules.

[0145] It should be noted that the establishment of PDU session connections and the implementation of call services require processing based on the Modem protocol stack. Therefore, when implementing the PDU session establishment methods provided in the embodiments of this application, the strategies and processing logic followed by the terminal device can be set in the Modem protocol stack. That is, the operations performed by the terminal device in the PDU session establishment methods provided in the following embodiments can all be completed in the Modem protocol stack.

[0146] also, Figure 3 The terminal device 100 shown can realize display functions through GPU, display screen 194, and application processor.

[0147] In addition, the terminal device 100 can perform shooting functions through an ISP, camera 193, video codec, GPU, display screen 194, and application processor.

[0148] also, Figure 3 The external memory interface 120 shown can be used to connect an external memory card, such as a Micro SD card, to expand the storage capacity of the terminal device 100. The external memory card communicates with the processor 110 through the external memory interface 120 to perform data storage functions.

[0149] also, Figure 3 The diagram shows that internal memory 121 can be used to store computer executable program code, which includes instructions. Processor 110 executes various functional applications and data processing of terminal device 100 by running the instructions stored in internal memory 121.

[0150] Specifically, in the technical solutions provided in the embodiments of this application, the data involved and the relevant instructions for implementing the PDU session establishment method can be pre-stored in the internal memory 121. The processor 110 executes the instructions stored in the internal memory 121, thereby enabling the terminal device 100 to execute the PDU session establishment method provided in the various embodiments of this application.

[0151] See also Figure 3 For example, button 190 includes a power button, volume buttons, etc. Button 190 can be a mechanical button or a touch button. Motor 191 can generate vibration to indicate. Indicator 192 can be an indicator light, which can be used to indicate charging status, power changes, etc., or to indicate messages, such as missed calls, notifications, etc.

[0152] See also Figure 3For example, the SIM card interface 195 is used to connect a SIM card or a USIM card. The SIM card can be inserted into or removed from the SIM card interface 195 to achieve contact and separation with the terminal device 100. The terminal device 100 can support one or N (N is an integer greater than 1) SIM card interfaces 195. That is, multiple SIM cards or USIM cards can be inserted into the terminal. Specifically, the technical solutions provided in the embodiments of this application can be implemented based on SIM cards or USIM cards.

[0153] This concludes the introduction to the hardware structure of terminal device 100. It should be understood that... Figure 3 The terminal device 100 shown is only an example. In a specific implementation, the terminal device 100 may have more or fewer components than shown in the figure, may combine two or more components, or may have different component configurations. Figure 4 The various components shown can be implemented in hardware, software, or a combination of hardware and software, including one or more signal processing and / or application-specific integrated circuits.

[0154] Figure 2 A flowchart of a communication method 400 provided by related technologies is shown. This method 400 can be applied to... Figure 3 The communication system shown and / or Figure 4 In the terminal device shown. See also Figure 2 Method 400 may include the following steps S401-S411.

[0155] For example, after the terminal device sends a PDU session establishment request to the network device, the terminal device can start a timer T3580, for example, with a duration of 16 seconds, and determine whether the network has responded based on whether a response message is received within the set duration. For example, each time the terminal device initiates a PDU session establishment request to the network, timer T3580 is started, and each time timer T3580 expires, the terminal device resends the PDU session establishment request, repeating the attempt a total of 4 times.

[0156] S401, the terminal device sends a PDU session establishment request to the network device.

[0157] Alternatively, the PDU session establishment request can be a PDU SESSION ESTABLISHMENT REQUEST message.

[0158] S402, the terminal device enables the timer.

[0159] Optionally, step S402 can also be: the terminal device starts timing. For example, the terminal device starting a timer can be expressed as the terminal device starting timing.

[0160] Alternatively, step S402 could also be: the terminal device waits for a certain period of time.

[0161] Specifically, this timer can be represented as timer T3580, but in practical applications it can also be other forms of timers. Timer T3580 allows the terminal device to send the PDU SESSIONESTABLISHMENT REQUEST message again after a certain delay. This certain time is not limited in this embodiment and can be 16 seconds, 21 seconds, 24 seconds, or other durations; 16 seconds is used as an example below. Furthermore, other related content of timer T3580 can be found in the specific descriptions of the relevant protocols, and will not be repeated here. Optionally, steps S401 and S402 can also be: the terminal device sends a PDU session establishment request to the network device and starts the timer. Steps S401 and / or S402 can also be referred to as the initial attempt.

[0162] S403, the terminal device sends a PDU session establishment request to the network device.

[0163] Since the network device has not responded to the terminal device within the preset time specified by the timer (or the terminal device has not received the PDU response message), it indicates that the network side failed to respond to the terminal device's PDU session establishment request within the specified time. The terminal device can then attempt to send the PDU session establishment request again. Optionally, step S403 can also be: if the terminal device does not receive the response message for the PDU session establishment request after the timer expires, it sends a PDU session establishment request to the network device.

[0164] Alternatively, step S403 can also be: if the terminal device does not receive a PDUSESSION ESTABLISHMENT ACCEPT message or a PDU SESSION ESTABLISHMENT REJECT message after the terminal device's timeout period ends, the terminal device sends a PDU SESSION ESTABLISHMENT REQUEST message to the network device. Specifically, the PDUSESSION ESTABLISHMENT REQUEST message can be sent based on the timeout duration exceeding a preset duration.

[0165] Alternatively, step S403 can also be: after waiting for a certain period of time, the terminal device sends a PDUSESSION ESTABLISHMENT REQUEST message to the network device. S404, the terminal device starts a timer.

[0166] The relevant description of step S404 can be found in step S402, and will not be repeated here.

[0167] Optionally, step S403 and / or step S404 may also be referred to as the first retry.

[0168] S405, the terminal device sends a PDU session establishment request to the network device.

[0169] The relevant description of step S405 can be found in step S403, and will not be repeated here.

[0170] S406, the terminal device enables the timer.

[0171] The relevant description of step S406 can be found in step S402, and will not be repeated here.

[0172] Optionally, steps S405 and / or S406 may also be referred to as a second retry.

[0173] S407, the terminal device sends a PDU session establishment request to the network device.

[0174] The relevant description of step S407 can be found in step S403, and will not be repeated here.

[0175] S408, the terminal device enables the timer.

[0176] The relevant description of step S408 can be found in step S402, and will not be repeated here.

[0177] Optionally, steps S407 and / or S408 may also be referred to as the third retry.

[0178] S409, the terminal device sends a PDU session establishment request to the network device.

[0179] The relevant description of step S409 can be found in step S403, and will not be repeated here.

[0180] S410, the terminal device enables the timer.

[0181] The relevant description of step S410 can be found in step S402, and will not be repeated here.

[0182] Optionally, step S409 and / or step S410 may also be referred to as the fourth retry.

[0183] S411, the terminal device enters the "PROCEDURE TRANSACTION INACTIVE" state and no longer sends PDU session establishment requests.

[0184] After the terminal device has retried a total of 4 times, it will enter the "PROCEDURE TRANSACTIONINACTIVE" state and will no longer send PDU session establishment requests.

[0185] If the data service of the terminal device is restarted and the terminal device initiates a PDU session establishment request to the network again, the specific process can still be executed according to the steps S401-S410 above.

[0186] In the aforementioned related technologies, if an anomaly occurs during the process of establishing a connection between the terminal device and the SA network PDU session, the protocol requires a 16-second wait before resending the PDU session establishment request. If no network response is received, the terminal device must wait another 16 seconds before retrying. This process can be repeated a maximum of four times. After four failed attempts, the terminal device enters the "PROCEDURE TRANSACTION INACTIVE" state and ceases to send PDU session establishment requests. In addition to the initial 16-second wait, the entire process requires four retries, totaling over 80 seconds, resulting in a lengthy process that hinders rapid recovery of PDU services. Furthermore, once the terminal device enters the "PROCEDURE TRANSACTION INACTIVE" state, it will no longer send PDU session establishment requests. At this point, the terminal device needs to be turned on and off by the user (i.e., the terminal device is restarted), its airplane mode needs to be turned on and off (i.e., the airplane mode is re-switched), or its data service switch needs to be turned off and on (i.e., the data service is restarted) before it will continue to send PDU session establishment requests.

[0187] Therefore, embodiments of this application provide a communication method that can be applied to... Figure 3 The communication system shown and / or Figure 5 The terminal device shown can solve the problem of frequent network unresponsiveness caused by network anomalies or poor environmental signals during the PDU data connection establishment process, or escape back to a lower standard network in advance, reducing the impact time of network anomalies and improving the user's service experience.

[0188] Figure 2 The flowchart shown is a communication method provided in an embodiment of this application, which can be applied to... Figure 3 The communication system shown and / or Figure 5 In the terminal device shown. See also Figure 4 The method 500 may include the following steps S501-S509.

[0189] S501, the terminal device sends a PDU session establishment request.

[0190] Optionally, after the terminal device attaches to the network device, the terminal device sends a PDU session establishment request to the network device. This PDU session establishment request can be a PDU SESSION ESTABLISHMENT REQUEST message. See also... Figure 6 Regarding the relevant description, the PDU session establishment request sent by the terminal device in step 501 can be the Mth PDU session establishment request sent, where M can be a positive integer less than N, and N can be a preset integer. Optionally, N can be negotiated between the terminal device and the 5G SA network or specified by the protocol (e.g., N can be 5), which is not limited in this application. For ease of explanation, the following example uses N=5 as an example.

[0191] For example, assuming N = 5, then M can be 1, 2, 3, or 4. When M is 1, the terminal device sends its first (i.e., initial) PDU session establishment request to the network device. When M is greater than 1 and less than 5, before the terminal device sends its Mth PDU session establishment request to the network device, it sends M-1 consecutive PDU session establishment requests without receiving a response from the network device. For example, when M is 2, after the terminal device sends its first PDU session establishment request to the network device without a response, it sends its second PDU session establishment request, and so on.

[0192] For ease of explanation, the following example illustrates step S501, in which the terminal device initiates the first (i.e., the first) PDU session establishment request to the network device.

[0193] It should be noted that, in this embodiment, the terminal device initiates a PDU session establishment request to the network device. In actual implementation, this is achieved by sending a PDU session establishment request message to a network element device within the network device. In other words, the PDU session establishment process involves signaling interaction between the terminal device and network elements (such as gNBs or access and mobility management function (AMF) network elements). For ease of explanation, the following description of the specific signaling interaction between the terminal device and network elements is omitted.

[0194] S502, the terminal device records the cell currently in which it is camped (i.e. the cell that has not responded after the timeout) as the first cell.

[0195] After step S501, the terminal device can execute step S502.

[0196] For example, step S502 can also be: if the terminal device does not receive a first response message within a first duration, the terminal device records the currently camped cell as the first cell. The first response message can be a PDUSESSION ESTABLISHMENT ACCEPT message or a PDU SESSION ESTABLISHMENT REJECT message, and the first duration can be 5 seconds, 8 seconds, 10 seconds, 16 seconds, 20 seconds, or other durations; this application does not limit this. The following description of the first response message is provided here; for ease of explanation, it will not be repeated below.

[0197] For example, step S502 can also be: if the terminal device does not receive the first response message within a first time period, the terminal device records the cell it is currently camping on. The cell it is currently camping on is the first cell.

[0198] For example, step S502 may also be: in response to the terminal device not detecting the first response message within a first time period, the terminal device records the currently camped cell as the first cell.

[0199] For example, step S502 can also be: after the terminal device sends the PDU session establishment request for the Mth time, the terminal device records the currently camped cell (i.e. the cell that has not responded after timeout) as the first cell.

[0200] For example, after step S501 and before step S502, the terminal device may also execute step S5011: the terminal device determines whether a first response message has been received within a first time period. That is, after executing step S501 and the terminal device sends the PDU session establishment request for the Mth time, it first executes step S5011: the terminal device determines whether a first response message has been received within a first time period. If the terminal device determines that a first response message has been received within the first time period, i.e., the early termination condition is met, the process ends; if the terminal device determines that no first response message has been received within the first time period, the terminal device continues to execute the above-mentioned step S502: the terminal device records the currently camped cell (i.e., the cell that has timed out and not responded) as the first cell. In addition, steps S5011 and S502 can also be executed simultaneously, which is not limited in this application.

[0201] It should be noted that the terminal device recording the currently camped cell (i.e., the cell that has timed out and not responded) as the first cell can mean that the terminal device determines the currently camped cell as the first cell. Furthermore, the terminal device recording the currently camped cell (or determining the currently camped cell) can also include various implementation methods.

[0202] For example, a terminal device can record the cell identifier of the cell it is currently camped on. By recording the cell identifier (such as the cell ID), the terminal device can accurately and directly determine the cell it is currently camped on.

[0203] For example, a terminal device can record information about the currently camped cell, including: cell signal strength (such as RSSI or RSRP), cell type information (such as macro cell, micro cell, or Pico cell), cell frequency information (such as uplink and downlink frequencies), neighbor cell information (neighbor cell cell ID and signal strength), cell status information (such as whether it is an active cell, whether it is under maintenance, etc.), cell load information (such as the number of users, bandwidth usage, etc.), and cell timestamp information. By recording one or more of the above information, the terminal device can evaluate the cell's coverage quality, resource allocation, etc. from multiple perspectives, and can also determine the currently camped cell after analyzing the above information.

[0204] S503, the terminal device performs the first Reattach.

[0205] After step S502, the terminal device may execute step S503.

[0206] Optionally, after the terminal device sends the PDU session establishment request, the terminal device performs the first Reattach. The specific Reattach process can refer to the relevant technologies or protocols described above, and will not be repeated here. It should be noted that steps S502 and S503 can be executed simultaneously or sequentially; this embodiment does not limit the order of steps S502 and S503.

[0207] S504, the terminal device sends a PDU session establishment request.

[0208] After step S503, the terminal device may execute step S504.

[0209] Optionally, after the terminal device successfully reattaches for the first time, the terminal device sends a PDU session establishment request to the network device. Specifically, the PDU session establishment request sent by the terminal device in step 505 may be the (M+1)th time the terminal device sends a PDU session establishment request to the network device. For example, it may be the second time the terminal device sends a PDU session establishment request to the network device.

[0210] Other related content in step S504 can be found in step S501, and will not be repeated here.

[0211] S505, the terminal device records the currently camped cell (i.e. the cell that was reattached for the first time) as the second cell.

[0212] After step S504, the terminal device may execute step S505.

[0213] Step S505 can be implemented in multiple ways. For example, step S505 can also be: if the terminal device does not receive the first response message within the second time period, the terminal device records the currently camped cell as the second cell.

[0214] For example, step S505 can also be: if the terminal device does not receive the first response message within the second time period, the terminal device records the cell it is currently camping on. The cell it is currently camping on is the second cell.

[0215] For example, step S505 may also be: in response to the terminal device not detecting the first response message within the second time period, the terminal device records the currently camped cell as the first cell.

[0216] For example, step S505 may also be: after the terminal device sends the PDU session establishment request for the M+1th time, the terminal device records the currently camped cell (i.e. the cell that has not responded after timeout) as the first cell.

[0217] For example, after step S504 and before step S505, the terminal device may also execute step S5041: the terminal device determines whether a first response message has been received within the second time period. That is, after executing step S504 and sending the PDU session establishment request for the M+1th time, the terminal device first executes step S5041: the terminal device determines whether a first response message has been received within the second time period. If the terminal device determines that a first response message has been received within the second time period, i.e., the early termination condition is met, the process ends; if the terminal device determines that no first response message has been received within the second time period, the terminal device continues to execute the above-mentioned step S505: the terminal device records the currently camped cell (i.e., the cell of the first Reattach) as the second cell. In addition, steps S5041 and S505 can also be executed simultaneously, which is not limited in this application.

[0218] Other related content in step S5041 can be found in step S5011, and will not be repeated here.

[0219] It should be noted that the terminal device recording the currently camped cell (i.e., the cell from the first reattach) as the second cell can mean that the terminal device determines the currently camped cell as the second cell. The second cell and the first cell can be the same or different. Whether they are the same or not can depend on factors such as the network conditions in the vicinity of the terminal device at that time and whether the location has changed. This application does not impose any restrictions.

[0220] S506, terminal devices disable the third duration of the first cell.

[0221] After step S505, the terminal device may execute step S506.

[0222] If the second cell is identical to the first, it indicates that the same cell failed to respond to the PDU session establishment request in both Attach attempts. This cell may have persistent network problems or failures, such as weak signal, significant interference, or equipment malfunction, preventing successful activation of data services. In this situation, the cell can be identified as a problem cell and added to a blacklist (i.e., disabled). Disabling this cell prevents users from frequently attempting to Attach to it when the network is unstable. This proactive fault handling mechanism can address network problems more quickly, reduce the impact on users, and thus improve the overall user experience.

[0223] Step S506 can be implemented in multiple ways. For example, step S506 can also be: when the first cell and the second cell are the same, the terminal device disables the third duration of the first cell.

[0224] For example, step S506 can also be: if the first cell and the second cell are the same, the terminal device disables the third duration of the first cell.

[0225] For example, step S506 may also be: in response to the terminal device recording that the currently camped cell is the second cell, the terminal device disables the first cell for a third duration, wherein the second cell is the same as the first cell.

[0226] For example, step S506 may also be: in response to the terminal device determining that the currently camped cell is the second cell, the terminal device disables the third duration of the first cell, wherein the second cell is the same as the first cell.

[0227] For example, after step S505 and before step S506, the terminal device may also execute step S5051: the terminal device determines whether the first cell and the second cell are the same. That is, after executing step S505 and recording that the currently camped cell is the second cell, the terminal device first executes step S5051: the terminal device determines whether the first cell and the second cell are the same. If the terminal device determines that the first cell and the second cell are the same, then the above-mentioned step S506 is executed; if the terminal device determines that the first cell and the second cell are the same, then the terminal device continues to execute the following step S509. In addition, steps S5051 and S506 can also be executed simultaneously, which is not limited in this application.

[0228] It should be noted that disabling the third duration of the first cell by the terminal device can mean that the terminal device does not initiate an Attach to the first cell within the third duration. Furthermore, disabling the third duration of the first cell by the terminal device can also include various implementation methods.

[0229] For example, the terminal device can add the first cell to the disabled list used for cell reselection for a preset duration. The preset duration can be a third duration.

[0230] For example, in some embodiments, the terminal device can add the frequency point of the first cell to the disabled list or blacklist for a preset duration. The preset duration can be a third duration.

[0231] It should be noted that disabling the third duration in the first cell is just one example. The third duration can be different, such as: 60 seconds, 120 seconds, 240 seconds, 360 seconds, 480 seconds, 600 seconds, 720 seconds, 7200 seconds, 28800 seconds, 86400 seconds, etc.

[0232] S507, within the third time interval, the terminal device performs a second reattach.

[0233] After step S506, the terminal device may execute step S507.

[0234] Because the cell that was first reattached (i.e., the first or second cell) is disabled by the terminal device within the third time period, the terminal device will not reattach to the cell it reattached to the first time after the second reattachment. Instead, it will reattach to other cells. In this way, the terminal device can reattach to other normal cells, thereby receiving the response message of the PDU session establishment request (the first response message) as soon as possible, thus improving the user's data service experience.

[0235] Optionally, if the first cell and the second cell are the same, the terminal device may perform a second Reattach within the third time period.

[0236] Optionally, after the terminal device determines that the cell in the first Reattach is the second cell, the terminal device performs a second Reattach, wherein the second cell is the same as the first cell.

[0237] The specific process of Reattach can be referred to the relevant technologies or relevant protocol provisions described above, and will not be repeated here. It should be noted that steps S506 and S507 can be executed simultaneously or sequentially. This application embodiment does not limit the order of steps S506 and S507.

[0238] S508, the terminal device sends a PDU session establishment request.

[0239] After step S507, the terminal device may execute step S508.

[0240] Optionally, after the terminal device successfully reattaches for the second time, the terminal device sends a PDU session establishment request. Specifically, this can be the (M+2)th time the terminal device sends the PDU session establishment request to the network device. More specifically, it can be the third time the terminal device sends the PDU session establishment request to the network device.

[0241] Other relevant details for step S508 can be found in step S501 and will not be repeated here.

[0242] It should be noted that after the terminal device sends the PDU session establishment request for the M+2th time, if the PDU connection is successfully established, the process ends. If the PDU connection is still not successfully established (including: receiving a message that refuses to establish a PDU connection, or not receiving a first response message within a certain period of time), the terminal device continues to execute the following step S509.

[0243] For example, after step S508, the terminal device may also execute step S5081: the terminal device determines whether a PDU connection has been successfully established. If the terminal device determines that a PDU connection has been successfully established, the process ends; if the terminal device determines that a PDU connection has not been successfully established, the terminal device continues to execute the following step S509.

[0244] S509, the terminal device disables SA capability.

[0245] After step S505 or step S508, the terminal device may execute step S509.

[0246] Alternatively, the terminal device disabling SA capability can also refer to the terminal device disabling the SA network.

[0247] After step S505, if the second cell is different from the first cell, it indicates that the two different cells near the terminal device failed to successfully respond to the PDU session establishment request in Attach. Since the possibility of two different cells simultaneously experiencing persistent network problems or failures is low, it is more likely that the terminal device is experiencing issues with the nearby 5G network environment, such as insufficient signal coverage, interference between cells, or widespread network misconfiguration. In this situation, measures such as disabling SA or 5G functionality can be taken. This means the terminal device will stop attempting to activate data services in the current network environment, preventing users from wasting time in an unstable 5G network. This proactive fault handling mechanism can promptly escape from a poor high-standard network to a low-standard network. Although this reduces the network standard, for such serious network problems, timely standard reduction actually minimizes the impact on users, ensuring basic data service usage and thus improving the overall user experience.

[0248] After step S508, since the original cell has been disabled so that the terminal device can attach to the new cell, if the terminal device still fails to establish a PDU connection after sending the PDU session establishment request for the M+2th time, it means that the two different cells near the terminal device failed to respond to the PDU session establishment request during the Attach process. Therefore, the terminal device should also execute step S509.

[0249] Step S509 can be implemented in various ways. For example, step S509 can also be: the terminal device disables the ability of a first network, wherein the first network is a 5G network. Specifically, the terminal device can store a list of disabled networks and a list of enabled networks. The terminal device can have an enabled or disabled state for different types of networks. For example, the state of the terminal device can include enabling or disabling the 5G network, enabling or disabling the 4G network.

[0250] For example, step S509 could also be: the terminal device does not initiate SA registration within the fourth time period. Specifically, after the fourth time period expires, SA capability can be restored, and the terminal device's customized parameters determine whether to initiate SA registration immediately.

[0251] For example, step S509 may also be: within the fourth time period, the terminal device no longer initiates a PDU session establishment request to the SA network, but initiates a PDU session establishment request to the LTE network.

[0252] The fourth duration can be preset by the terminal device, negotiated between the terminal device and the network, or stipulated by the protocol; this application does not impose any restrictions on this. For example, the fourth duration can be 60 seconds, 120 seconds, 240 seconds, 360 seconds, 480 seconds, 600 seconds, 720 seconds, 7200 seconds, 28800 seconds, 86400 seconds, etc.

[0253] In summary, unlike related technologies, in this embodiment, the terminal device can terminate SA network registration in advance, disable SA, turn off SA capabilities, and not initiate registration on the SA network. At this time, the terminal device can fall back to the LTE network and perform data services, achieving a rapid escape, thereby reducing the abnormal time caused by the network not responding to the PDU session establishment request and improving the user experience.

[0254] Furthermore, it should be noted that in this embodiment of the application, if the early termination condition is met, that is, after the process ends, the terminal device can perform the operations after receiving the PDU SESSION ESTABLISHMENT ACCEPT message or the PDUSESSION ESTABLISHMENT REJECT message in accordance with the protocol. This embodiment of the application will not be described in detail.

[0255] Furthermore, users can manually unblock SA on their terminal devices by performing some preset operations. In some optional embodiments, after the 5G-corresponding SANR standard is disabled, the terminal device can restore SA functionality under certain circumstances, including: the SIM card or USIM card being removed, airplane mode being turned on and then off, the device being restarted, the SIM card or USIM card being switched, or the 5G switch being turned off and then on again. That is, if the user turns airplane mode on and off, SA can also be restored. It is evident that in some cases, user behavior may affect the terminal device's processing flow. For example, when a user senses a problem with data services, they may toggle airplane mode on and off again between the above processes S501-S509. Since toggling airplane mode on and off triggers a new network search process, the above processes S501-S509 may be interrupted by the toggling of airplane mode on and off. Therefore, after detecting that airplane mode has been toggled on and off, the terminal device can perform the corresponding processing flow.

[0256] Since the terminal device has had its airplane mode switched on and off by the user, it's likely that the device has already performed a reattach during this process. Therefore, it's unnecessary for the terminal device to reattach again and then perform operations such as disabling the SA network or disabling the cell. Consequently, the processing flow can be adjusted accordingly, further reducing the time affected by the anomaly.

[0257] It should be noted that the airplane mode on a terminal device can be turned on and off at any time. Several implementation methods are described below. For example, Figure 2 The flowchart shown is a communication method provided in an embodiment of this application, which can be applied to... Figure 3 The communication system shown and / or Figure 6 In the terminal device shown. See also Figure 6 The method 600 may include the following steps S601-S616.

[0258] S601, the terminal device sends a PDU session establishment request.

[0259] S602, the terminal device determines whether it has received the first response message within the first time period.

[0260] S603, the terminal device records the currently camped cell (i.e. the cell that has not responded after timeout) as the first cell.

[0261] S604, the terminal device performs its first Reattach.

[0262] S605, the terminal device sends a PDU session establishment request.

[0263] S606, the terminal device determines whether it has received the first response message within the second time period.

[0264] Steps S602 and S606 can also be omitted.

[0265] The relevant descriptions of steps S601-S606 can be found in the relevant content of steps S501-S504 respectively. Specifically, step S602 can be found in step S5011 and step S606 can be found in step S5041. They will not be repeated here.

[0266] It should be noted that although airplane mode on a terminal device can be turned on and off at any time, it is better to minimize the impact of the anomaly if it happens before the second Reattach is executed.

[0267] Therefore, in some embodiments, after step S606, the terminal device may execute step S614:

[0268] S614, the terminal device determines whether the flight mode of the terminal device has been turned on and off once.

[0269] Before the terminal device determines whether it has received the first response message within the second time period, the terminal device may have already had its airplane mode turned on and off by the user. The terminal device can determine after step S606 whether its airplane mode has been turned on and off once. For example, after the terminal device determines whether it has received the first response message within the second time period, if the terminal device determines that it has received the first response message within the second time period, the early termination condition is met, and the process ends; if the terminal device determines that it has not received the first response message within the second time period, the terminal device continues to execute the above step S614.

[0270] The terminal device can typically determine whether the flight mode has been turned on or off once through the following methods: system status monitoring (the terminal device can maintain a status flag to record the current state of the flight mode, and the system will update the flag whenever the flight mode state changes), event listening (the terminal device can register a broadcast receiver to listen for system broadcasts of flight mode state changes; when the flight mode is turned on or off, the system will send a corresponding broadcast, and the terminal device can capture these events and update its state), log recording (the terminal device can access the system log to check the records of flight mode state changes), API calls (the terminal device can provide an API interface to query the current state of the flight mode; by periodically calling these APIs, the state changes of the flight mode can be determined), and setting option recording (the terminal device can determine the state changes of the flight mode through the on / off state of setting options), etc. Specifically, the terminal device can check the initial state of the flight mode before or simultaneously with step S601. Then, through the above implementation methods, it can monitor the state changes of the flight mode, and when a determination is needed, check the number of changes to determine whether the flight mode has been turned on or off once.

[0271] It should be noted that if the terminal device's airplane mode has been turned on and off once, the terminal device will continue to execute step S615 below; if the terminal device's airplane mode has not been turned on and off once, the terminal device will continue to execute step S607 below. In addition, steps S614 and S606 can be executed simultaneously or sequentially. This application embodiment does not limit the order of steps S614 and S606.

[0272] S615, the terminal device determines whether the terminal device is attached to the first cell.

[0273] If the terminal device attaches to the first cell after switching on / off airplane mode, the terminal device continues to execute step S616 below; if the terminal device does not attach to the first cell, the terminal device returns to execute step S602 above.

[0274] S616, the terminal device determines whether it has received the first response message within the fifth time period.

[0275] Optionally, after the terminal device attaches to the first cell, it sends a PDU session establishment request to the network device. The terminal device can determine whether it receives a first response message within a fifth time interval after sending the PDU session establishment request to the network device. This fifth time interval can be 5 seconds, 8 seconds, 10 seconds, 16 seconds, 20 seconds, or other durations; this application does not limit the duration. It should be noted that sending the PDU session establishment request to the network device can also be a separate action; this is not explicitly stated here for simplicity. Figure 7 middle.

[0276] If the terminal device receives the first response message within the fifth time period, the early termination condition is met, and the process ends; if the terminal device detects that it has not received the first response message within the fifth time period, the terminal device continues to execute the following step S609.

[0277] S607, the terminal device records the cell that was reattached for the first time as the second cell.

[0278] S608, the terminal device determines whether the first cell and the second cell are the same.

[0279] S609, terminal devices disable the third duration of the first cell.

[0280] S610, within the third time interval, the terminal device performs a second reattach.

[0281] S611, the terminal device sends a PDU session establishment request.

[0282] S612, the terminal device determines whether the PDU connection has been successfully established.

[0283] S613, the terminal device disables SA capability.

[0284] Steps S608 and S612 can also be omitted.

[0285] The relevant descriptions of steps S607-S613 can be found in steps S505-S509. Specifically, step S608 can be found in step S5051, and step S612 can be found in step S5081. They will not be repeated here.

[0286] It should be noted that the above process is described using the example of checking whether airplane mode has been turned on or off after the first Reattach and before the second Reattach. In reality, airplane mode on and off of the terminal device can happen at any time, so steps S614-S616 can also be executed after or simultaneously with any of steps S601, S602, S603, S604, or S605.

[0287] If steps S614-S616 are executed before step S604, since the terminal device has not yet performed step S604 (i.e., the first Reattach), step S609 cannot be executed directly according to the above process. Instead, step S604 should be executed first to prevent unnecessary cell disabling and network degradation.

[0288] If steps S614-S616 are executed after step S604 and before step S607, since the first Reattach has already occurred, steps S614-S616 can be consistent with the above process (steps S614-S616 are executed after step S606 and before step S607).

[0289] After step S607, the terminal device may not execute steps S614-S616, that is, it may not process the flight mode for the terminal in the process, and may continue the process as usual.

[0290] Furthermore, it's important to note that although steps S614-S616 are executed within the aforementioned timeframe, the user's operation to switch airplane mode on or off does not occur between steps S614 and S616. In fact, the user can operate the terminal device's airplane mode before step S614. That is, when the user operates airplane mode before step S614, the terminal device can first record that airplane mode was switched on / off, whether the terminal device attached to the first cell, and whether the terminal device received the first response message within the fifth time period. Moreover, the terminal device may not necessarily execute the attach procedure at this time. For example, if the user switches airplane mode on / off very quickly, the terminal device may not have enough time to complete the attach procedure and therefore cannot attach to the first cell. In this case, it can be recorded that the terminal device did not attach to the first cell. However, even if the user turns off airplane mode within the fifth time period, it does not affect recording whether the terminal device received the first response message within the fifth time period, because the terminal device has already sent a PDU session establishment request, and can still receive the corresponding response message even if airplane mode is turned off.

[0291] For example, referring to step S601, the terminal device can first attach to the first network device of the first cell and send a PDU session establishment request to the first network device. Then, referring to step S602, if the terminal device does not receive a first response message for the first PDU session establishment request within a first time period, the user can perform a first operation (i.e., turning airplane mode on and off). In response to the user's first operation, the terminal device can reattach to the first cell and then send a second PDU session establishment request to the first network device of the first cell; or the terminal device may attach to the second cell and then send a second PDU session establishment request to the second network device of the second cell. The terminal device can record whether it receives a response message corresponding to the second PDU session establishment request within a second time period, depending on the actual situation. Then, referring to step S604, in response to the terminal device not receiving a first response message within the first time period, the terminal device reattaches to the first network device. Understandably, the terminal device has actually reattached twice at this point. One of the reattaches was caused by the user's first operation. In other words, if the terminal device attaches to the first cell and does not receive a response message for the PDU session establishment request within the preset time, it indicates that the first cell is likely a problem cell and the cell can be disabled directly without any other recording or judgment steps.

[0292] In summary, when a mobile phone switches to airplane mode, the PDU session establishment process is interrupted. This is because activating airplane mode causes the device to perform a completely new network search process, thus affecting the PDU's connection status. Normally, upon entering airplane mode, the PDU's resources are released, leading to the termination of the PDU session establishment process. Therefore, this application embodiment also provides the aforementioned optimization mechanism and adaptively handles situations where airplane mode is switched on and off at different times, in order to ensure the stability of the PDU connection as much as possible during airplane mode switching.

[0293] In other situations, other user behaviors may also affect the terminal device's processing flow. For example, the user may be conducting a call between processes S501-S509. Since performing processes S501-S509 during a user's call may affect the user's call experience, in order to ensure the quality of the user's call as much as possible, the terminal device can perform corresponding processing procedures when it detects that the user is in a call.

[0294] For example, Figure 2 The flowchart shown is a communication method provided in an embodiment of this application, which can be applied to... Figure 3 The communication system shown and / or Figure 7In the terminal device shown. See also Figure 8 The method 700 may include the following steps S701-S717.

[0295] S701, the terminal device sends a PDU session establishment request.

[0296] S702, the terminal device determines whether it has received the first response message within the first time period.

[0297] S703, the terminal device records the cell it is currently camped on (i.e. the cell that has not responded after the timeout) as the first cell.

[0298] Step S702 can also be omitted.

[0299] The relevant descriptions of steps S701-S703 can be found in the relevant content of steps S501-S502 respectively. Specifically, step S702 can be found in step S5011, and will not be repeated here.

[0300] It should be noted that in some embodiments, the terminal device may already be in a call state before it records the currently camped cell (i.e., the cell that has timed out and not responded) as the first cell. Since reattaching affects the call quality of the terminal device, it is necessary to determine whether the terminal device is in a call before reattaching, so as to ensure the user's call experience as much as possible.

[0301] Therefore, in some embodiments, after the terminal device records the currently camped cell (i.e. the cell that has timed out and not responded) as the first cell in step S703, the terminal device may first execute the following step S714.

[0302] S714, the terminal device determines that the terminal device is in the process of a call.

[0303] For example, step S714 can also be: the terminal device detects whether the terminal device is currently in a call.

[0304] Specifically, step S714 can be implemented in various ways, including: system status monitoring (the terminal device can maintain a status flag to monitor the call status), event listening (the terminal device can register a broadcast receiver to listen for system broadcasts of changes in the call status; the terminal device can capture events and update the status), log recording, and API calls (the terminal device can use an API interface to query the current call status). Specifically, the terminal device can check its call status before, after, or simultaneously with step S703.

[0305] If the terminal device is in a call, the terminal device continues to execute step S715 below; if the terminal device is not in a call, the terminal device continues to execute step S717 below.

[0306] S715, the terminal device waited for the sixth time.

[0307] Optionally, the terminal device starts a timer, wherein the preset duration of the timer is the sixth duration.

[0308] Optionally, the terminal device may not reattach within six hours after it determines that it is in the middle of a call.

[0309] The sixth duration can be 5 seconds, 8 seconds, 10 seconds, 16 seconds, 20 seconds, or other durations; this application does not impose any restrictions.

[0310] S716, the terminal device determines whether it has received the first response message within the sixth time period.

[0311] Optionally, the terminal device determines whether it has received the first response message within six time intervals after it determines that it is in the middle of a call.

[0312] If the terminal device receives the first response message within the sixth time period, the early termination condition is met, and the process ends; if the terminal device does not receive the first response message within the sixth time period, the terminal device returns to execute the above step S714.

[0313] S717, the terminal device determines whether the terminal device has successfully established a PDU connection.

[0314] If the terminal device has successfully established a PDU connection, the process ends; if the terminal device has not successfully established a PDU connection, the terminal device continues to execute step S704 below. The steps executed by the terminal device after the process ends can be found in the relevant protocol's description of the PDU session establishment process, and will not be repeated here.

[0315] S704, the terminal device performs its first reattach.

[0316] S705, the terminal device sends a PDU session establishment request.

[0317] S706, the terminal device determines whether it has received the first response message within the second time period.

[0318] S707, the terminal device records the cell that was first reattached as the second cell.

[0319] S708, the terminal device determines whether the first cell and the second cell are the same.

[0320] S709, terminal devices disable the third duration of the first cell.

[0321] S710, within the third time interval, the terminal device performs a second reattach.

[0322] S711, the terminal device sends a PDU session establishment request.

[0323] S712, the terminal device determines whether the PDU connection has been successfully established.

[0324] S713, the terminal device disables SA capability.

[0325] Steps S706, S708, and S712 can also be omitted.

[0326] The relevant descriptions of steps S704-S713 can be found in steps S503-S509. Specifically, step S706 can be found in step S5041, step S708 can be found in step S5051, and step S712 can be found in step S5081. They will not be repeated here.

[0327] It should be noted that the above process is described using the case of checking whether a call is in progress before the first Reattach (i.e., before step S704) as an example. In reality, the terminal device can be in a call at any time, so steps S714-S717 can also be executed at any time after step S701 and before step S704. However, checking the call status as close to step S704 as possible before step S704 can identify the call status as accurately as possible.

[0328] The terminal device can also execute steps S714 and S704 simultaneously, that is: if the terminal device does not detect that it is in a call, the terminal device performs the first Reattach; if the terminal device detects that it is in a call, the terminal device does not perform the first Reattach and continues to execute step S715. Optionally, the terminal device performs the first Reattach in response to the terminal device not being in a call.

[0329] Similarly, the terminal device can also execute the check at any time after step S704 and before step S710, that is, before the second Reattach, to check whether the terminal device is in a call. However, checking the call status as close as possible to step S704 before step S704 can identify the call status as accurately as possible.

[0330] Similarly, the terminal device can also execute steps S714 and S710 simultaneously, that is: if the terminal device does not detect that it is in a call, the terminal device performs a second Reattach; if the terminal device detects that it is in a call, the terminal device does not perform a second Reattach and continues to execute step S715. Optionally, the terminal device performs a second Reattach in response to the terminal device not being in a call.

[0331] Furthermore, the terminal device can detect whether it is in a call before the first Reattach and before the second Reattach, that is, execute steps S714-S717 in both cases.

[0332] In summary, this application resolves compatibility issues related to call processes and PDU session establishment. In this application, the terminal device assesses the call status before reattaching and reassesses the current PDU status after the call ends. This application enables real-time updates to the PDU status during a call, ensuring the latest connection status is available at the end of the call. This method effectively improves the stability and reliability of data services, ensuring call quality while minimizing the impact of PDU connection failures.

[0333] To address the potential problems in the aforementioned abnormal scenarios and considering actual user experience, the following section designs corresponding handling strategies for scenarios such as PDU network connection failure, user re-toggling airplane mode in PDU network connection failure scenarios, or user making a call in PDU network connection failure scenarios. Specific implementations are described in the following embodiments, which are exemplified by using an NR network as the first network and an LTE network as the second network. It should be noted that the scenarios implemented in the current product are a subset of the entire invention solution; different strategies can be customized for other scenarios. The specific embodiments described below do not represent all aspects of this solution.

[0334] First Implementation: In the event of PDU network connection failure, the same scenario applies to both the first and second cells.

[0335] In the first embodiment, an escape design is implemented for a scenario where network unresponsiveness causes an anomaly during the PDU session establishment process. For example, Figure 2 The flowchart shown is a communication method provided in an embodiment of this application, which can be applied to... Figure 3 The communication system shown and / or Figure 8 In the terminal device shown. See also Figure 9 The method 800 may include the following steps S801-S812.

[0336] S801, the terminal device sends the first PDU session establishment request.

[0337] Specifically, the terminal device sends a PDU SESSION ESTABLISHMENT REQUEST message to the first network device. The first network device refers to relevant equipment within the first network (including but not limited to base stations).

[0338] It should be noted that the relevant description of step S801 can be referred to step S501, and will not be repeated here.

[0339] S802, the terminal device starts the first timer.

[0340] Specifically, after the terminal device sends the first PDU session establishment request, the terminal device starts a first timer of a preset duration, where the preset duration is the first duration.

[0341] S803, the terminal device records the information of the current cell.

[0342] Specifically, after the terminal device starts the first timer, the terminal device records the currently camped cell (i.e. the cell that has not responded after the timeout) as the first cell.

[0343] For example, when the first timer expires, it means that the terminal device has not received the first response message within the preset time. At this time, the terminal device can perform a Reattach to resend the PDU session establishment request.

[0344] For example, after a first period of time following the terminal device sending the first PDU session establishment request, the terminal device determines the current cell as the first cell.

[0345] It should be noted that the relevant description of step S803 can be referred to step S502, and will not be repeated here.

[0346] S804, the terminal device performs the first Reattach.

[0347] Specifically, after the terminal device records the information of the current cell, the terminal device performs the first Reattach.

[0348] It should be noted that the relevant description of step S804 can be referred to step S503, and will not be repeated here.

[0349] S805, the terminal device sends a second PDU session establishment request.

[0350] Specifically, after the terminal device performs the first reattach, the terminal device sends a PDUSESSION ESTABLISHMENT REQUEST message to the first network device. The first network device refers to relevant equipment within the first network (including but not limited to base stations).

[0351] It should be noted that the relevant description of step S805 can be referred to step S504, and will not be repeated here.

[0352] S806, the terminal device starts the second timer.

[0353] Specifically, after the terminal device sends the second PDU session establishment request, the terminal device starts a timer of a preset duration, where the preset duration is the second duration. The second duration may or may not be equal to the first duration.

[0354] For example, when the second timer times out, it means that the terminal device has not received the first response message within a preset time after performing a Reattach. At this time, the terminal device can proceed to step S807.

[0355] S807, the terminal device records the information of the current cell.

[0356] Specifically, after the terminal device starts the second timer, the terminal device records the currently camped cell (i.e. the cell that has timed out and has not responded) as the second cell.

[0357] For example, after a second duration following the terminal device sending the second PDU session establishment request, the terminal device determines the current cell as the second cell.

[0358] It should be noted that the relevant description of step S807 can be referred to step S505, and will not be repeated here.

[0359] S808, disable the third duration of the first cell.

[0360] Specifically, if the first and second cells are identical, the third duration in the first cell is disabled.

[0361] Optionally, since the first cell and the second cell are the same, the terminal device disables the third duration of the first cell.

[0362] It should be noted that the relevant description of step S808 can be referred to step S506, and will not be repeated here.

[0363] S809, the terminal device sends a third PDU session establishment request.

[0364] Specifically, within the third time period after the terminal device disables the first cell, the terminal device sends a PDU SESSION ESTABLISHMENT REQUEST message to the second network device. The second network device is related equipment of the first network (including but not limited to base stations), but the second network device is different from the first network device. The first network can be a 5G network.

[0365] It should be noted that the relevant description of step S809 can be referred to step S508, and will not be repeated here.

[0366] S810, the terminal device starts the third timer.

[0367] Specifically, after the terminal device sends the second PDU session establishment request, the terminal device starts a timer of a preset duration, where the preset duration can be the Nth duration, and N is a positive integer. This embodiment does not limit the duration of the Nth duration.

[0368] S811, the terminal device disables SA capability.

[0369] Specifically, if the terminal device does not receive the first response message within the Nth time period, the terminal device disables the SA capability.

[0370] It should be noted that the relevant description of step S811 can be referred to step S509, and will not be repeated here.

[0371] S812, Terminal device attaches to third network device.

[0372] Specifically, after or simultaneously with the terminal device disabling its SA capability, the terminal device attaches to a third network device, which is a related device of the second network (including but not limited to a base station). The second network can be a 4G network.

[0373] According to the solution provided in the first embodiment, when the two unresponsive cells during the PDU session establishment process are the same cell, the terminal device can disable that cell for a certain period of time. During this period, the terminal device can reattach to other cells and send PDU session establishment requests to those cells. If a PDU connection is successfully established during this process, it indicates that there is a problem with the network of the first cell; if the first response message is still not received, it indicates that there may be a problem with the first network. The terminal device can then terminate the PDU session establishment process early and fall back to the LTE network for registration, reducing the impact on user services.

[0374] Second embodiment: Different scenarios for the first and second cells when the PDU fails to establish a network connection.

[0375] In the first embodiment, an escape design is implemented for a scenario where network unresponsiveness causes an anomaly during the PDU session establishment process. For example, Figure 2 The flowchart shown is a communication method provided in an embodiment of this application, which can be applied to... Figure 3 The communication system shown and / or Figure 9 In the terminal device shown. See also Figure 10 The method 900 may include the following steps S901-S909.

[0376] S901, the terminal device sends the first PDU session establishment request.

[0377] Specifically, the terminal device sends a PDU SESSION ESTABLISHMENT REQUEST message to the first network device. The first network device refers to relevant equipment within the first network (including but not limited to base stations).

[0378] It should be noted that the relevant description of step S801 can be referred to step S501, and will not be repeated here.

[0379] S902, the terminal device starts the first timer.

[0380] Specifically, after the terminal device sends the first PDU session establishment request, the terminal device starts a first timer of a preset duration, where the preset duration is the first duration.

[0381] S903, the terminal device records the current cell information.

[0382] Specifically, after the terminal device starts the first timer, the terminal device records the currently camped cell (i.e. the cell that has not responded after the timeout) as the first cell.

[0383] For example, when the first timer expires, it means that the terminal device has not received the first response message within the preset time. At this time, the terminal device can perform a Reattach to resend the PDU session establishment request.

[0384] For example, after a first period of time following the terminal device sending the first PDU session establishment request, the terminal device determines the current cell as the first cell.

[0385] It should be noted that the relevant description of step S903 can be referred to step S502, and will not be repeated here.

[0386] S904, the terminal device performs the first Reattach.

[0387] Specifically, after the terminal device records the information of the current cell, the terminal device performs the first Reattach.

[0388] It should be noted that the relevant description of step S904 can be referred to step S503, and will not be repeated here.

[0389] S905, the terminal device sends a second PDU session establishment request.

[0390] Specifically, after the terminal device performs the first reattach, it sends a PDUSESSION ESTABLISHMENT REQUEST message to the second network device. The second network device is a related device of the first network (including but not limited to base stations), but it differs from the first network device. The first network can be a 5G network.

[0391] It should be noted that the relevant description of step S905 can be referred to step S504, and will not be repeated here.

[0392] S906, the terminal device starts the second timer.

[0393] Specifically, after the terminal device sends the second PDU session establishment request, the terminal device starts a timer of a preset duration, where the preset duration is the second duration. The second duration may or may not be equal to the first duration.

[0394] For example, when the second timer times out, it means that the terminal device has not received the first response message within a preset time after performing a Reattach. At this time, the terminal device can proceed to step S907.

[0395] S907, the terminal device records the current cell information.

[0396] Specifically, after the terminal device starts the second timer, the terminal device records the currently camped cell (i.e. the cell that has timed out and has not responded) as the second cell.

[0397] For example, after a second duration following the terminal device sending the second PDU session establishment request, the terminal device determines the current cell as the second cell.

[0398] It should be noted that the relevant description of step S907 can be referred to step S505, and will not be repeated here.

[0399] S908, the terminal device disables SA capability.

[0400] Specifically, if the first cell and the second cell are different, the terminal device disables SA capability.

[0401] Optionally, due to the differences between the first and second cells, the terminal device disables SA capability.

[0402] It should be noted that the relevant description of step S908 can be referred to step S509, and will not be repeated here.

[0403] S909, Terminal device attaches to third network device.

[0404] Specifically, after or simultaneously with the terminal device disabling its SA capability, the terminal device attaches to a third network device, which is a related device of the second network (including but not limited to a base station). The second network can be a 4G network.

[0405] According to the solutions provided in the first and second embodiments, when the same cell fails to respond twice during the PDU session establishment process, the terminal device can disable that cell for a certain period. During this period, the terminal device can reattach to other cells and send PDU session establishment requests to those cells. If a PDU connection is successfully established during this process, it indicates that there is a problem with the network of the first cell; if the first response message is still not received, it indicates that there may be a problem with the first network. The terminal device can then terminate the PDU session establishment process early and fall back to the LTE network for registration, reducing the impact on user services.

[0406] It should also be noted that in the embodiments of this application, "greater than" can be replaced with "greater than or equal to", "less than or equal to" can be replaced with "less than", or "greater than or equal to" can be replaced with "greater than", and "less than" can be replaced with "less than or equal to".

[0407] The various embodiments described herein can be independent solutions or combinations thereof based on their inherent logic, and all such solutions fall within the protection scope of this application.

[0408] It is understood that the methods and operations implemented by the access network device in the above method embodiments can also be implemented by components (e.g., chips or circuits) that can be used in the access network device. Similarly, the methods and operations implemented by the terminal device in the above method embodiments can also be implemented by components (e.g., chips or circuits) that can be used in the terminal device. Furthermore, the methods and operations implemented by the core network device in the above method embodiments can also be implemented by components (e.g., chips or circuits) that can be used in the core network device.

[0409] The method embodiments provided in this application have been described above. The apparatus embodiments provided in this application will be described below. It should be understood that the description of the apparatus embodiments corresponds to the description of the method embodiments. Therefore, any content not described in detail can be referred to the method embodiments above. For the sake of brevity, it will not be repeated here.

[0410] The foregoing mainly described the solutions provided in the embodiments of this application from the perspective of interaction between devices. It is understood that each device, such as a transmitting or receiving device, includes corresponding hardware structures and / or software modules to perform the aforementioned functions. Those skilled in the art should recognize that, based on the units and algorithm steps of the examples described in conjunction with the embodiments disclosed herein, this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is executed by hardware or by computer software driving hardware depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of protection of this application.

[0411] This application embodiment can divide the transmitting or receiving device into functional modules based on the above method examples. For example, each function can be divided into its own functional modules, or two or more functions can be integrated into one processing module. The integrated modules can be implemented in hardware or as software functional modules. It should be noted that the module division in this application embodiment is illustrative and only represents one logical functional division; other feasible division methods may exist in actual implementation. The following description uses the division of functional modules according to each function as an example.

[0412] Figure 11 This is a schematic block diagram of a communication device 800 provided in an embodiment of this application. The device 800 can be used to perform the actions performed by the base station or access network equipment in the method embodiments described above. The device 800 includes a transceiver unit 810 and a processing unit 820. The transceiver unit 810 is used to perform transceiver-related operations on the terminal device side in the method embodiments described above. The transceiver unit 810 can also be referred to as a communication interface or communication unit. The processing unit 820 is used to perform data processing, and the processing unit 820 is used to perform processing-related operations on the terminal device side in the method embodiments described above.

[0413] The transceiver unit 810 is used to initiate the Mth PDU session establishment request to the network device, where M is a positive integer less than N and N is a preset integer. In some embodiments, when M is greater than 1 and less than N, the device 800 fails to establish PDU sessions with the network device M-1 consecutive times before the transceiver unit 810 initiates the Mth PDU session establishment request to the network device.

[0414] The processing unit 820 is used to execute corresponding processing strategies in the case of PDU connection abnormality. The processing strategies include stopping the initiation of PDU session establishment requests to the network device and initiating PDU session establishment requests to a second network different from the network device.

[0415] In some embodiments, the apparatus 800 may further include a counting unit, which counts once each time the apparatus 800 fails to establish a PDU session with the network device, and accumulates the cumulative number of failures M in the case of the Mth failure.

[0416] In some embodiments, the apparatus 800 may further include a storage unit for a corresponding processing strategy.

[0417] The apparatus 800 according to the embodiments of this application can correspond to the execution of the method described in the embodiments of this application, and the above and other operations and / or functions of the units in the apparatus 800 are respectively for implementing the corresponding process of the method, which will not be described again here for the sake of brevity.

[0418] Figure 11 This is a schematic structural diagram of a communication device 900 provided in an embodiment of this application. The communication device 900 includes: a processor 910, a memory 920, a communication interface 930, and a bus 940.

[0419] In one possible implementation, Figure 10 The processor 910 in the illustrated device 900 can correspond to Figure 11 The processing unit 820 in the device 800. Figure 10 The communication interface 930 in the device 900 shown can correspond to Figure 11 The transceiver unit 810 in the device 800.

[0420] The processor 910 can be connected to the memory 920. The memory 920 can be used to store the program code and data. Therefore, the memory 920 can be a storage unit inside the processor 910, an external storage unit independent of the processor 910, or a component that includes both the storage unit inside the processor 910 and the external storage unit independent of the processor 910.

[0421] Optionally, device 900 may further include bus 940. The memory 920 and communication interface 930 can be connected to processor 910 via bus 940. Bus 940 can be a peripheral component interconnect (PCI) bus or an extended industry standard architecture (EISA) bus, etc. Bus 940 can be divided into address bus, data bus, control bus, etc. For ease of representation, ​ The symbol is represented by only one line, but this does not mean that there is only one bus or one type of bus.

[0422] It should be understood that in the embodiments of this application, the processor 910 may be a central processing unit (CPU). The processor may also be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor. Alternatively, the processor 810 may employ one or more integrated circuits to execute relevant programs to implement the technical solutions provided in the embodiments of this application.

[0423] The memory 920 may include read-only memory and random access memory, and provides instructions and data to the processor 910. A portion of the processor 910 may also include non-volatile random access memory. For example, the processor 910 may also store device type information.

[0424] When the device 900 is running, the processor 910 executes computer execution instructions in the memory 920 to perform the operation steps of the above method through the device 800.

[0425] It should be understood that the device 900 according to the embodiments of this application may correspond to the device 800 in the embodiments of this application, and the above and other operations and / or functions of each unit in the device 800 are respectively the corresponding processes for implementing the method, which will not be described in detail here for the sake of brevity.

[0426] Optionally, in some embodiments, this application also provides a computer-readable medium storing program code that, when run on a computer, causes the computer to perform the methods described in the above aspects.

[0427] Optionally, in some embodiments, this application also provides a computer program product, the computer program product comprising: computer program code, which, when run on a computer, causes the computer to perform the methods in the above aspects.

[0428] In this embodiment, the terminal device or network device includes a hardware layer, an operating system layer running on top of the hardware layer, and an application layer running on top of the operating system layer. The hardware layer may include hardware such as a central processing unit (CPU), a memory management unit (MMU), and memory (also called main memory). The operating system layer can be any one or more computer operating systems that implement business processing through processes, such as Linux, Unix, Android, iOS, or Windows. The application layer may include applications such as browsers, address books, word processing software, and instant messaging software.

[0429] This application does not impose any particular limitation on the specific structure of the execution subject of the method provided in this application embodiment. As long as it is possible to communicate according to the method provided in this application embodiment by running a program that records the code of the method provided in this application embodiment. For example, the execution subject of the method provided in this application embodiment can be a terminal device or a network device, or a functional module in a terminal device or network device that can call and execute a program.

[0430] Various aspects or features of this application can be implemented as methods, apparatus, or articles of manufacture using standard programming and / or engineering techniques. As used herein, the term "article of manufacture" can encompass a computer program accessible from any computer-readable device, carrier, or medium. For example, computer-readable media can include, but are not limited to: magnetic storage devices (e.g., hard disks, floppy disks, or magnetic tapes), optical discs (e.g., compact discs (CDs), digital versatile discs (DVDs), etc.), smart cards, and flash memory devices (e.g., erasable programmable read-only memory (EPROMs), cards, sticks, or key drives, etc.).

[0431] The various storage media described herein may represent one or more devices and / or other machine-readable media used for storing information. The term "machine-readable media" may include, but is not limited to, wireless channels and various other media capable of storing, containing and / or carrying instructions and / or data.

[0432] It should be understood that the processor mentioned in the embodiments of this application can be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor or any conventional processor.

[0433] It should also be understood that the memory mentioned in the embodiments of this application can be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. Non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. Volatile memory can be random access memory (RAM). For example, RAM can be used as an external cache. By way of example and not limitation, RAM can include a variety of forms, such as: static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous linked dynamic random access memory (SLDRAM), and direct rambus RAM (DR RAM).

[0434] It should be noted that when the processor is a general-purpose processor, DSP, ASIC, FPGA, or other programmable logic device, discrete gate or transistor logic device, or discrete hardware component, the memory (storage module) can be integrated into the processor.

[0435] It should also be noted that the memory described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0436] Those skilled in the art will recognize that the units and steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of protection of this application.

[0437] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0438] In the embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection of apparatuses or units may be electrical, mechanical, or other forms.

[0439] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of the embodiments of this application, depending on actual needs.

[0440] In addition, the functional units in the various embodiments of this application can be integrated into one unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0441] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a computer software product. This computer software product is stored in a storage medium and includes several instructions that cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium may include, but is not limited to, various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0442] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0443] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A communication method, characterized in that, include: The terminal device attaches to the first network device in the first cell; The terminal device sends a first protocol data unit (PDU) session establishment request to the first network device. If the terminal device does not receive the first response message of the first PDU session establishment request within a first time period, the terminal device reattaches to the first network device. The terminal device sends a second PDU session establishment request to the first network device; If the terminal device does not receive a second response message for the second PDU session establishment request within a second time period, the terminal device disables the first cell.

2. The method according to claim 1, characterized in that, After the terminal device attaches to the first network device of the first cell, it also includes: The terminal device sends a third PDU session establishment request to the first network device; If the terminal device does not receive the third response message of the third PDU session establishment request within the third time period, the terminal device reattaches to the second network device of the second cell. The second cell is different from the first cell, and both the second network device and the first network device belong to the first network. The terminal device sends a fourth PDU session establishment request to the second network device; If the terminal device does not receive the fourth response message for the fourth PDU session establishment request within the fourth time period, the terminal device disables the SA capability.

3. The method according to claim 1, characterized in that, After the terminal device disables the first cell, the method further includes: The terminal device reattaches to a third network device in a third cell, which is different from the first cell; The terminal device sends a fifth PDU session establishment request to the third network device; If the terminal device does not receive the fifth response message of the fifth PDU session establishment request within the seventh time period, the terminal device disables the SA capability.

4. The method according to claim 3, characterized in that, The method further includes: When the terminal device receives the fifth response message within the seventh time period, the terminal device establishes a PDU session.

5. The method according to claim 2 or 3, characterized in that, After the terminal device disables SA capability, the following is also included: The terminal device is attached to the third network device of the second network, which is different from the first network.

6. The method according to any one of claims 1 to 5, characterized in that, After the terminal device reattaches to the first network device, the process further includes: In response to the user's first operation, the terminal device sends a sixth PDU session establishment request to the first network device, and the terminal device does not receive a sixth response message for the sixth PDU session establishment request within a fifth time period; In response to the terminal device detecting the first operation, the terminal device determines that the terminal device has not received the sixth response message of the sixth PDU session establishment request within the fifth time period; The terminal device disables the first cell, including: In response to a sixth response message indicating that the terminal device has not received the sixth PDU session establishment request within a fifth time period, the terminal device disables the first cell.

7. The method according to claim 6, characterized in that, The first operation includes: turning off the flight mode of the terminal device after turning it on; removing the USIM card and inserting it back in; removing the SIM card and inserting it back in; turning off the terminal device and turning it on; switching the USIM card to a different USIM card; switching the SIM card to a different SIM card; or turning off the 5G switch and turning it on.

8. The method according to any one of claims 1 to 7, characterized in that, Before the terminal device reattaches to the first network device, the method further includes: The terminal device receives the first incoming call; After a sixth period of time since the terminal device received the first call, the terminal device terminates the first call. In response to the terminal device ending the first incoming call, the terminal device reattaches to the first network device.

9. The method according to any one of claims 1 to 8, characterized in that, Before the terminal device attaches to the first network device of the first cell, it also includes: The terminal device sends M PDU session establishment requests to the first network, where M is a positive integer.

10. The method according to any one of claims 1 to 9, characterized in that, If the terminal device does not receive a first response message for the first PDU session establishment request within a first time period, the method further includes: At the first moment, the terminal device records the cell in which the terminal device is camped at the first moment; If the terminal device does not receive a second response message for the second PDU session establishment request within a second time period, the method further includes: At the second moment, the terminal device records the cell in which the terminal device is camped, and the second moment is later than the first moment; The terminal device disables the first cell, including: In response to the fact that the cell in which the terminal device camps at the first time moment is the same as the cell in which the terminal device camps at the second time moment, the terminal device disables the first cell.

11. The method according to any one of claims 1 to 10, characterized in that, The terminal device disables the first cell, including: During the third time period, the terminal device does not send an Attach request to the first cell.

12. The method according to any one of claims 1 to 11, characterized in that, The terminal device disabling SA capability includes: The terminal device does not send an Attach request to the first network; The terminal device sends an Attach request to a second network, which is different from the first network.

13. The method according to any one of claims 1 to 12, characterized in that, The PDU session establishment request includes: PDU SESSION ESTABLISHMENT REQUEST message.

14. The method according to any one of claims 1 to 13, characterized in that, The response message for the PDU session establishment request includes either a PDU SESSION ESTABLISHMENT ACCEPT message or a PDU SESSION ESTABLISHMENT REJECT message.

15. The method according to any one of claims 1 to 14, characterized in that, The first network is a fifth-generation standalone 5G SA network, and the second network is a long-term evolution LTE network.

16. A terminal device, characterized in that, The terminal device includes: a memory and a processor coupled to the memory; the memory stores a computer program, and when the processor executes the computer program, it causes the terminal device to implement the method as described in any one of claims 1 to 15.

17. A chip system, characterized in that, The chip system is applied to the terminal device, and the chip system includes one or more processors, the one or more processors being used to invoke computer instructions to cause the terminal device to perform the method as described in any one of claims 1 to 15.

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