Network registration method and terminal

Abstract

Provided in the present application are a network registration method and a terminal. In the method, the number of attempts for MO detach is reduced, and the duration for MO detach to wait for a network response can also be shortened, thereby shortening a procedure in which a network has no response to MO detach, so that a user equipment can search for and register on networks of other standards more quickly, resuming network camping more quickly and providing a better data service experience.

Description

Network registration method and terminal

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on January 3, 2024, with application number 202410008377.5 and application name “Network Registration Method and Terminal” and the Chinese patent application filed with the China Patent Office on March 18, 2024, with application number 202410315166.6 and application name “Network Registration Method and Terminal”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of terminals and communication technologies, and in particular to a network registration method and terminal. Background Art

[0003] Mobile communication networks have gone through multiple stages of development. For example, the second-generation mobile communication network (2G network) evolved to the third-generation mobile communication network (3G network), the fourth-generation mobile communication network (4G network), and finally the fifth-generation mobile communication network (5G network). The evolution from one generation of mobile communication network to another is like moving from one stage to another, and each stage brings new features and improvements.

[0004] In some cases, a terminal switches from one network to another. How to improve the efficiency of switching the terminal from one network to another is worth discussing. Summary of the Invention

[0005] The embodiments of the present application provide a network registration method and a terminal to improve the efficiency of a terminal switching from one network to another.

[0006] In a first aspect, an embodiment of the present application provides a network registration method, including: a terminal initiates an Nth deregistration request to a first network, and the deregistration request is used to disconnect a first data connection with the first network; when the first network does not respond to the Nth deregistration request, the terminal is in a preset area, and the first network is a preset network, the terminal releases the packet switched PS domain link with the first network and initiates a network search; wherein, the PS domain link is used to realize the first data connection; the preset network includes a network whose network quality in the preset area is lower than a preset condition; when a second network is searched, the terminal initiates a registration request to the second network, and the registration request is used to establish a second data connection with the second network; wherein, N is a positive integer less than Z, and Z is the maximum number of attempts by the terminal to initiate a deregistration request to the first network specified in the standard protocol, and the standard protocol specifies that the conditions for the terminal to release the PS domain link with the first network include: the deregistration request initiated by the terminal is responded to by the first network, or, none of the Z deregistration requests initiated by the terminal are responded to.

[0007] In the above embodiment, the preset area may be an area where the network quality of the first network is poor. In this case, the first network may be the low-standard network described in FIG. 10 or the weak network described in FIG. 11 . When the network quality of network 1 is poor, the terminal reduces the number of attempts to initiate a deregistration (Mo detach) request to network 1 (from Z to N). This can shorten the time the terminal waits for the first network to respond to the deregistration request, allowing the terminal to more quickly ignore network 1's response to the deregistration request, initiate a new network search, and then register with network 2, achieving faster network switching. The reason for faster network switching is that when the network quality of network 1 is poor, the first N deregistration requests issued by the terminal are likely to be unreceivable by network 1, and therefore unable to respond to the terminal's deregistration requests. According to the previous standard protocol, after the Nth deregistration request, it is necessary to continue to initiate ZN deregistration requests that are likely to be unresponsive to network 1. Only when network 1 fails to respond to Z registration requests can the terminal ignore the response and initiate a new network search.

[0008] In combination with the first aspect, in some embodiments, the network quality in the preset area is lower than the preset conditions, including the network that has been disconnected from the network in the preset area, or the network quality in the preset area is lower than the preset conditions, including the network coverage in the preset area is lower than the preset level.

[0009] The above embodiments take into account the scenario where the development of mobile communication networks may make existing standard protocols no longer applicable. Alternatively, they also take into account the scenario where mobile communication networks are unevenly configured in different regions, resulting in existing standard protocols being unable to fully adapt to different regions.

[0010] The development of mobile communication networks involves the gradual phase-out of older networks to make way for the emergence and rollout of new ones. This phase-out and rollout of new networks occurs gradually to ensure a smooth transition for users. For example, the Global System for Mobile Communications (GSM) and Wideband Code Division Multiple Access (WCDMA) are both standard network standards in the mobile communications industry, corresponding to 2G (second-generation) and 3G (third-generation) networks, respectively. GSM and WCDMA were once widely used in the mobile communications industry, providing reliable voice communications and basic data transmission services. With the development of new-generation mobile communication networks such as 4G (LTE) and 5G (NR), GSM and WCDMA have been phased out in some regions, but they continue to be used in some areas or specific scenarios. When 4G networks became popular, 2G and 3G networks were not immediately shut down, but instead coexisted for a period of time to provide services to users who were still using them. As time goes by and new technologies mature, old networks gradually withdraw from mobile communication networks, and mobile communication networks turn to the popularization and dominance of new networks.

[0011] Uneven regional deployment of mobile communication networks can include: While some networks haven't been decommissioned, their coverage in some areas is worse than that of decommissioned networks. For example, in some countries, while 2G / 3G networks are being decommissioned, 4G / 5G networks haven't. Consequently, in some areas, 4G / 5G coverage is worse than 2G / 3G coverage.

[0012] In combination with the first aspect, in some embodiments, the method further includes: when the first network does not respond to the Nth deregistration request and the terminal is not in the preset area, or when the first network does not respond to the Nth deregistration request and the first network is not the preset network standard, the terminal initiates the N+1th deregistration request to the first network.

[0013] In the above embodiment, if the network quality of the first network is not poor, the original network configuration can be used to initiate more than N deregistration requests. Deregistration requests initiated after the Nth time may be responded to by the first network. In this way, the first network can know that the terminal wishes to disconnect from it, approve the deregistration request, and notify the terminal. This ensures that the registration information on the terminal and the network remains consistent.

[0014] In combination with the first aspect, in some embodiments, the method further includes: the terminal starts a T3321 timer after initiating an i-th deregistration request to the first network, where i is greater than or equal to 1 and less than or equal to N; when the T3321 timer reaches a preset duration and the terminal does not receive a response from the first network to the i-th deregistration request and i is less than N, the terminal initiates an i+1-th deregistration request to the first network; when the terminal is in the preset area and the first network is the preset network standard, the preset duration is a first duration; when the terminal is not in the preset area, or when the first network is not the preset network, the preset duration is a second duration; the second duration is greater than the first duration; the second duration is the duration of the T3321 timer specified in the standard protocol.

[0015] In the above embodiment, in addition to reducing the number of times deregistration requests are initiated, the time waiting for the network (first network) to respond after initiating the deregistration request is also shortened, thereby further shortening the time the terminal waits for the first network to respond to the deregistration request, allowing the terminal to ignore network 1's response to the deregistration request more quickly, initiate a new network search, and then register on network 2, bringing a better data service experience.

[0016] In combination with the first aspect, in some embodiments, the network standard of the second network is higher than the network standard of the first network, or the coverage of the second network in the preset area is greater than the coverage of the first network in the preset area.

[0017] In combination with the first aspect, in some embodiments, the second duration is 15 seconds and the first duration is 5 seconds.

[0018] In combination with the first aspect, in some embodiments, Z is equal to 5, and N is equal to 1.

[0019] In combination with the first aspect, in some embodiments, the method further includes: before the terminal initiates a deregistration request to the first network for the first time, the terminal determines that the data service activation fails.

[0020] In combination with the first aspect, in some embodiments, the registration request is further used to establish a voice call connection; the voice call connection is used to fall back from the second network to the first network for a voice call.

[0021] In the above embodiment, the registration request is a joint registration request as described below. Joint registration can provide greater fault tolerance and switching flexibility when switching from network 1 to network 2. For example, if the voice call quality of a terminal on network 2 deteriorates, it can fall back to network 1 to continue the voice call.

[0022] In combination with the first aspect, in some embodiments, the first network is a 2G or 3G network, and the second network is a 4G network or a 5G network; when the first network is a 2G network, the network standard of the first network includes the Global System for Mobile Communications GSM network standard; when the first network is a 3G network, the network standard of the first network includes the Wideband Code Division Multiple Access WCDMA network standard.

[0023] In a second aspect, the present application provides a network registration method, the method comprising: a terminal initiates an Nth deregistration request to a first network, the deregistration request being used to disconnect a first data connection with the first network; when the first network does not respond to the Nth deregistration request and the first network is disconnected from the network in the area where the terminal is located, or when the first network does not respond to the Nth deregistration request and the first network is not disconnected from the network in the area where the terminal is located, but the network coverage of the first network in the area where the terminal is located is less than a preset level, the terminal releases the packet switching PS domain link with the first network and initiates a network search; wherein the PS domain link Used to implement the first data connection; the preset network includes a network whose network quality in the preset area is lower than a preset condition; when a second network is searched, the terminal initiates a registration request to the second network, and the registration request is used to establish a second data connection with the second network; wherein N is a positive integer less than Z, and Z is the maximum number of attempts specified in the standard protocol for the terminal to initiate a deregistration request to the first network, and the standard protocol specifies that the conditions for the terminal to release the PS domain link with the first network include: the deregistration request initiated by the terminal is responded to by the first network, or Z deregistration requests initiated by the terminal are not responded to.

[0024] In the above embodiment, when the network coverage of the first network is small (caused by network withdrawal or uneven network distribution), the network quality of the first network will be poor. When the network quality of network 1 is poor, the terminal reduces the number of attempts to initiate a deregistration (Mo detach) request to network 1 (from Z to N), which can shorten the time the terminal waits for the first network to respond to the deregistration request, allowing the terminal to ignore network 1's response to the deregistration request more quickly, initiate a new network search, and then register with network 2, thus achieving network switching more quickly. The reason for achieving network switching more quickly is that when the network quality of network 1 is poor, the first N deregistration requests issued by the terminal are likely to be unreceivable by network 1, and therefore cannot respond to the terminal's deregistration request. If the previous standard protocol is followed, it is necessary to continue to initiate ZN deregistration requests after the Nth time, which are likely to be unresponsive to network 1. Only when none of the Z registration requests are responded to by network 1 can the terminal ignore the response and initiate a new network search.

[0025] In combination with the second aspect, in some embodiments, the network coverage of the first network in the area where the terminal is located is less than a preset level includes: the network coverage of the first network in the area where the terminal is located is less than the network coverage of other networks except the first network.

[0026] In combination with the second aspect, in some embodiments, when the first network does not respond to the Nth deregistration request, the first network does not exit the network in the area where the terminal is located, and the network coverage of the first network in the area where the terminal is located is greater than a preset level, the terminal initiates the N+1th deregistration request to the first network.

[0027] In combination with the second aspect, in some embodiments, the network coverage of the first network in the area where the terminal is located is greater than a preset level, including: there are other networks other than the first network in the area where the terminal is located, and the network coverage is smaller than the network coverage of the first network in the area where the terminal is located.

[0028] In a third aspect, the present application provides a network registration method. In some embodiments, the method includes: a terminal initiates N deregistrations to a first network; when it is determined that no response to the Nth deregistration has been received from the first network, the terminal initiates registration to a second network; wherein N is a positive integer less than Z, and Z is the standard number of registrations specified in the first network standard. The first network standard specifies that after the first registration initiated by the terminal to the first network fails, the conditions for stopping registration include: there is a successful registration between the second registration and the Zth registration, or Z-1 registrations fail.

[0029] In the above embodiment, the number of deregistrations is reduced, and when registration with the first network fails, registration with the second network can be performed without being restricted by the network standard and attempts to register with the first network can be continued.

[0030] In combination with the third aspect, in some embodiments, N is equal to 1.

[0031] In combination with the third aspect, in some embodiments, the method further includes: after the terminal initiates the i-th deregistration to the first network, starting a timer; the value of i is an integer from 1 to N-1; when the timer reaches a first preset time and no response is received from the first network to the i-th deregistration, the terminal determines that the i-th registration has failed and starts to initiate the i+1-th registration to the first network.

[0032] In combination with the third aspect, in some embodiments, the first preset time is less than a second preset time, and the second preset time is a registration waiting time specified by the first network standard.

[0033] In the above embodiment, the waiting time after each registration is reduced. When there is a problem with the first network, the second network can be registered as soon as possible, so that the terminal maintains network connection.

[0034] In combination with the third aspect, in some embodiments, when the first network is a 2G network, the first network standard is a Global System for Mobile Communications (GSM) network standard; or, when the first network is a 3G network, the first network standard is a Wideband Code Division Multiple Access (WCDMA) network standard.

[0035] In combination with the third aspect, in some embodiments, the second network is an LTE network or an NR network.

[0036] In combination with the third aspect, in some embodiments, Z is equal to 5.

[0037] In combination with the third aspect, in some embodiments, when the first network standard is the GSM network standard or the WCDMA network standard, the first preset time is 5 seconds, and the second preset time is 15 seconds.

[0038] In the above implementation, the number of Mo detach attempts is reduced, and the time Mo Detach waits for network response is shortened, thereby significantly shortening the Mo Detach network unresponsiveness process, allowing the UE to search for and register with other networks faster, resume network resident status faster, and bring a better data service experience.

[0039] In a fourth aspect, an embodiment of the present application provides a terminal comprising: one or more processors and a memory; the memory is coupled to the one or more processors, the memory being used to store computer program code, the computer program code comprising computer instructions, the one or more processors calling the computer instructions to enable the terminal to execute the method implemented in the first aspect.

[0040] In a fifth aspect, an embodiment of the present application provides a computer-readable storage medium comprising instructions, which, when executed on a terminal, causes the terminal to execute the method implemented in the first aspect.

[0041] In a sixth aspect, an embodiment of the present application provides a chip system, which is applied to a terminal, and the chip system includes one or more processors, which are used to call computer instructions to enable the terminal to execute the method implemented in the first aspect. The chip system can be a SoC (system-on-chip). The processor can include a modem processor (also known as a modem or baseband chip).

[0042] In a seventh aspect, an embodiment of the present application provides a computer program product comprising instructions, which, when executed on a terminal, enables the terminal to execute the method implemented in the first aspect.

[0043] It is understandable that the terminal provided in the fourth aspect, the computer storage medium provided in the fifth aspect, the chip system provided in the sixth aspect, and the computer program product provided in the seventh aspect are all used to execute the methods provided in the embodiments of the present application. Therefore, other beneficial effects that can be achieved can be referred to the beneficial effects of the corresponding methods and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] FIG1 shows a schematic diagram of a scenario of switching from one network to another;

[0045] FIG2 is an exemplary mobile communication network provided by an embodiment of the present application;

[0046] FIG3 shows a process flow chart of GPRS Mo Detach in standard GSM / WCDMA;

[0047] FIG4 is a schematic diagram showing a scenario in which a terminal cannot deregister and locate an available network when the signal of a low-standard network is weak;

[0048] FIG5 shows a process flow chart of GPRS Mo Detach in the modified network configuration;

[0049] FIG6 is a schematic diagram showing a scenario in which a terminal quickly locates an available network when the signal of a low-standard network is weak;

[0050] FIG7 shows an exemplary flow chart of Mo Detach of a terminal in usage scenario 1;

[0051] FIG8 is a schematic diagram showing a terminal switching from one low-standard network to another low-standard network;

[0052] FIG9 shows a schematic diagram of a terminal switching from a low-standard network to another high-standard network;

[0053] FIG10 shows an exemplary flow chart of Mo Detach of a terminal in usage scenario 2;

[0054] FIG11 shows an exemplary flow chart of Mo Detach of a terminal in usage scenario 3;

[0055] FIG12 is a schematic diagram of the structure of the terminal provided in an embodiment of the present application. DETAILED DESCRIPTION

[0056] In one solution, for a terminal (user equipment, UE) that supports at least two mobile communication networks, if the signal of the connected network (mobile communication network) becomes weak or interrupted, resulting in data service being interrupted or even difficult to carry out, the terminal can initiate a deregistration request to the connected network to disconnect the data connection with the connected network and send a registration request to a network other than the connected network. The registration request is used to attempt to register with the other network, establish a new data connection with the other network, and then use the data transmission service provided by the other network. In this way, the terminal can maintain the continuity of the data connection to complete the data service.

[0057] The deregistration of a terminal from one network and then registering with another network can be called network switching. This network switching usually occurs when the area to which the terminal belongs changes. As shown in Figure 1, when the user is on a high-speed train and the train is heading from high-speed railway station A to high-speed railway station B, the terminal will move from area A covered by the 4G / 5G network to area B covered by the 2G / 3G network. In area A, the terminal can display a user interface 11. Referring to the network indicator 115 in the user interface 11, this indicates that the terminal has established a data connection A with the 4G network. When the terminal leaves area A and enters area B, when the terminal attempts to send a message 112 to other terminals through data connection A, a loading indicator 111 appears next to the message box. And the loading indicator 111 does not disappear for a long time (from 17:59-18:00), which indicates that the signal of the 4G network to which the terminal is connected has weakened or the signal is interrupted. At this time, the terminal can initiate a deregistration request to the connected 4G network to disconnect data connection A.

[0058] Continuing with Figure 1, after entering area B, the terminal can search for an available 3G network and initiate a registration request to the 3G network to establish a new data connection (data connection B) with the 3G network. In area B, the terminal can display user interface 12. Referring to the network indicator 113 in user interface 12, this indicates that the terminal has established data connection B with the 3G network. As shown in user interface 12, the terminal successfully sends a message 112 to the other terminal via data connection B.

[0059] It should be understood that after a terminal registers with a 3G network, if area B is large enough and the 3G network signal is strong, the terminal can maintain data connection B longer. However, as the train leaves area B, the 3G network signal gradually weakens. For example, referring to user interface 13, when a terminal attempts to send a message 131 to another terminal via data connection B, a loading indicator 111 appears around the message box. This indicates that the signal of the 3G network to which the terminal is connected has weakened. At this point, the terminal can initiate a deregistration request to the connected 3G network to disconnect data connection B and attempt to register with the network covered by the next area.

[0060] It should be noted that after establishing a data connection with the connected network, the terminal can connect to the packet switching (PS) domain of the connected network through the link established by the data connection. The PS domain provides the technology and processing mechanism for transmitting data, thereby enabling data transmission between the terminal and the connected network. Once the terminal is successfully deregistered, it will no longer be able to continue data services on the connected network. Among them, the link established through the data connection can also be called a PS domain link.

[0061] The aforementioned data services refer to services or operations performed through the PS domain of the connected network. Traffic volume is typically used to measure the amount of data transmitted across the network to complete the data service. Common data services include browsing the web, sending emails, watching videos, and using social media.

[0062] Since data services are completed through the PS domain of the connected network, the deregistration request mentioned above for disconnecting the data connection can be called a PS domain deregistration request. The registration request mentioned above for establishing the data connection can be called a PS domain registration request (PS Attach). The deregistration in the PS domain deregistration can also be called deregistration.

[0063] Currently, the networks supported by the terminal include, but are not limited to, at least two of the following: 2G, 3G, 4G, and 5G networks. In the future, this may include more available mobile communication networks, which are not limited here. The following, in conjunction with Figure 2, describes the relevant content involved in establishing a data connection with the network via a PS domain registration request, and the relevant content involved in disconnecting the data connection with the network via a PS domain deregistration request.

[0064] Here, the 5G network is used as an example for explanation. For networks other than the 5G network, please refer to the description of the 5G network and will not be repeated here.

[0065] As shown in Figure 2, a 5G network may include a 5G base station, a 5G core network (5G core network, 5GC) and other 5G components.

[0066] A 5G base station can be a next-generation NodeB (gNB). A 5G base station can connect to both a terminal and a 5G core network. The 5G base station performs signal forwarding and scheduling, enabling the terminal to communicate with the 5G core network.

[0067] The 5G core network is the central control unit of the 5G network, responsible for managing and controlling the operation of the entire network. For example, the PS domain in a 5G network relies on the support of the 5G core network to achieve data transmission between the terminal and the 5G core network.

[0068] An exemplary process for a terminal to establish a data connection with a 5G network includes the following:

[0069] When the terminal wants to connect to the 5G network and start data transmission, it first needs to establish a physical connection with the 5G base station. Subsequently, the terminal sends a PS domain registration request through the physical connection. The PS domain registration request is a message sent by the terminal to the connected 5G base station to indicate to the 5G network that the terminal wants to connect to the 5G network and use the data services in the PS domain. The PS domain registration request contains the terminal's identification information (such as the International Mobile Equipment Identity IMSI) and PS domain service requirements. The PS domain service requirement refers to requesting the 5G network to provide the terminal with data connection services in the PS domain to ensure that the terminal can perform data transmission.

[0070] Then, the 5G base station will preliminarily verify the identity of the terminal and the legitimacy of the PS domain registration request based on the PS domain registration request. After the verification is passed, the PS domain registration request will be sent from the 5G base station to the 5G core network. The 5G core network will then process the PS domain registration request: including further verifying the identity of the terminal, checking the PS domain service requirements, authorizing and allocating corresponding resources (such as IP addresses, etc.) to generate configuration information. If the registration is successful, the 5G core network will return the configuration information to the 5G base station. After the 5G base station receives the configuration information returned by the 5G core network, it configures the resources involved in the terminal's data transmission according to the configuration information.

[0071] An exemplary process for disconnecting a terminal from a 5G network includes the following:

[0072] First, the terminal sends a PS domain deregistration request to the connected 5G base station. This PS domain deregistration request contains the terminal's identification information and the deregistration reason, notifying the 5G base station that it wishes to deregister from the PS domain and disconnect its data connection. The 5G base station processes the PS domain deregistration request. If the 5G base station agrees to the deregistration, it notifies the 5G core network of the terminal's deregistration information.

[0073] The 5G core network then determines whether to approve the deregistration based on the terminal's identifier and deregistration reason in the deregistration information and generates a deregistration response. This deregistration response contains the result of the PS deregistration operation, such as deregistration success or failure. If deregistration is successful, the 5G core network updates the terminal's registration status. This informs the 5G core network that the terminal has been deregistered and its data connection has been disconnected. The 5G core network then sends the deregistration response to the terminal via the 5G base station.

[0074] After receiving the deregistration response, the terminal performs subsequent operations based on the result of the PS deregistration operation: if the result of the PS deregistration operation is a successful deregistration, the terminal releases the PS domain link with the 5G network to disconnect the data connection with the 5G network. If the result of the PS deregistration operation is a deregistration failure, the terminal can retry PS domain deregistration. Here, the relevant content involved in the deregistration failure can be referred to the following description of Figure 2 and its related content, which is not repeated here.

[0075] Referring again to FIG. 2 , a 4G network may include a 4G base station, a 4G core network (evolved packet core, EPC), and other 4G components.

[0076] A 4G base station can be an evolved Node B (eNB), which can connect to both the terminal and the 4G core network. The 4G base station performs signal forwarding and scheduling, enabling the terminal to communicate with the 4G core network.

[0077] The 4G core network is the central control unit of the 4G network, responsible for managing and controlling the operation of the entire network. For example, the PS domain in a 4G network relies on the support of the 4G core network to achieve data transmission between terminals through the control and management of the 4G core network.

[0078] The process of establishing or disconnecting a data connection between the terminal and the 4G network is similar to the process of establishing or disconnecting a data connection with the 5G network. You can refer to the process of establishing or disconnecting a data connection between the terminal and the 5G network and change 5G to 4G.

[0079] Referring again to FIG. 2 , a 2G / 3G network may include components such as a 2G / 3G base station and a 2G / 3G core network.

[0080] A 2G base station can be a base transceiver station (BTS), while a 3G base station can be a NodeB. Terminals can connect to a 2G / 3G base station. The 2G / 3G base station forwards and dispatches signals, enabling terminals to communicate with the 2G / 3G core network.

[0081] It should be noted that the network standards used to implement communications in 2G networks include the Global System for Mobile Communications (GSM) network standard. GSM uses Time Division Multiple Access (TDMA) technology, enabling 2G networks to provide services such as data transmission and voice calls.

[0082] 3G networks utilize wideband code division multiple access (WCDMA) technology. WCDMA utilizes code division multiple access (CDMA) technology, enabling 3G networks to provide faster data transmission (compared to 2G networks) and voice services.

[0083] The network standards used for communication in 4G networks include the Long-Term Evolution (LTE) network standard. LTE utilizes an Internet Protocol (IP) network architecture and Orthogonal Frequency Division Multiple Access (OFDMA) technology, enabling 4G networks to provide faster data transmission (compared to 3G networks) and more stable voice services (compared to 3G networks).

[0084] The network standards used for communication in 5G networks include the New Radio (NR) network standard. NR uses a brand-new wireless access technology, enabling services such as high-speed data transmission and stable voice calls.

[0085] Among them, the data transmission service provided by the 2G / 3G / 4G / 5G network is based on the aforementioned PS domain. In the 2G / 3G network, the PS domain is also called the general packet radio service (GPRS) domain. The voice call service provided by the 2G / 3G network is based on the circuit switched (CS) domain. The voice call service provided by the 4G network is mainly completed in the IP multimedia subsystem (IMS) domain through VoLTE technology. The voice call service provided by the 5G network is mainly completed in the IMS domain through VoNR technology.

[0086] The preceding content introduces the network standards used in existing networks (such as 2G / 3G / 4G / 5G networks). The following describes how terminals based on each network standard (GSM / WCDMA / LTE / NR) implement network switching.

[0087] When a terminal on a standard GSM / WCDMA / LTE / NR network fails to respond to data service activation on a live network (e.g., 2G / 3G / 4G / 5G network), it attempts to initiate a mobile terminal-initiated deregistration (Mo Detach) in the PS domain to the connected network (GSM for 2G networks, WCDMA for 3G networks, LTE for 4G networks, and NR for 5G networks) and reregister (reattach) to an available network to restore data services. However, because the connected network does not respond to the Mo Detach initiated by the terminal, the terminal remains in the deregistration attempt state for a long time.

[0088] It should be noted that the deregistration actively initiated by the PS domain mobile terminal may also be referred to as Deregistration (Detach).

[0089] When attempting to deregister, the terminal cannot attempt to search and register under other network standards, making it impossible for the terminal to connect to other network standards (for example, a higher-standard network than the connected network), thereby affecting the terminal's data services.

[0090] The GSM or WCDMA standard stipulates that after a terminal (UE) initiates a Mo Detach attempt to register and fails, it needs to continue to initiate Mo Detach attempts to register. After each Mo Detach attempt to register, the terminal must wait h seconds (usually 15 seconds) before initiating the next Mo Detach attempt to register again. After x (usually 5) registration attempts have failed, the 2G / 3G network's response to the deregistration can be ignored, and then the terminal can attempt to register with a network other than the 2G / 3G network, such as a 4G network or a 5G network. This process can be as shown in the following Figure 3.

[0091] As shown in FIG3 , the process of a terminal initiating Mo Detach in a standard GSM or WCDMA includes steps S1 to S7 .

[0092] S1. The UE initiates a Mo Detach request to the network and starts the T3321 timer (15 seconds). It is expected that the terminal will receive a response from the network (GSM for 2G networks, WCDMA for 3G networks) before the T3321 timer expires.

[0093] In some implementations, if there is no response to data service activation on a standard GSM network, the terminal can attempt to initiate a Mo Detach request to the 2G network to request disconnection from the 2G network. If there is no response to data service activation on a standard WCDMA network, the terminal can attempt to initiate a Mo Detach request to the 3G network to request disconnection from the 3G network.

[0094] When initiating Mo Detach, the terminal also starts the T3321 timer to measure time. When the time measured by the T3321 timer reaches the agreed time (15 seconds), the terminal is triggered to perform related operations.

[0095] When the number of Mo Detach attempts is less than the maximum number of attempts, the related operation is to initiate Mo Detach again. Refer to the following description of steps S2 to S4.

[0096] When the number of times Mo Detach is initiated is equal to the maximum number of attempts, the relevant operation is to no longer wait for the network response, directly release the link and initiate a new network search registration. Refer to the following description of step S5. It should be noted that when the time measured by the T3321 timer does not reach the protocol time (15s), if the network's response to Mo Detach is received, the terminal can make corresponding processing based on the response and reset the number of times Mo Detach is initiated. Among them, the content of the corresponding processing based on the response can refer to the aforementioned description of the deregistration response and its related content. It will not be repeated here.

[0097] S2. While the T3321 timer is in effect, the terminal does not receive a response to the Mo Detach request initiated by the network, causing the T3321 timer to time out once.

[0098] That is, if the terminal does not receive a response to the Mo Detach request from the network (2G network or 3G network) before the T3321 timer expires, the terminal records that the T3321 timer has expired once, indicating that the terminal has failed in its first attempt to initiate Mo Detach to register.

[0099] S3. The UE initiates a Mo Detach to the network for the second time and restarts the T3321 timer (15 seconds). It is expected that the terminal will receive a response from the network (GSM for 2G networks, WCDMA for 3G networks) before the T3321 timer expires.

[0100] S4.T3321 timer times out twice.

[0101] In step S4, the T3321 timer times out twice includes: before the T3321 timer times out for the second time, when the terminal does not receive a response to the Mo Detach sent by the network (2G network or 3G network), the terminal records the number of T3321 timer timeouts plus 1, from 1 to 2.

[0102] The UE then initiates a Mo Detach request to the network (2G or 3G network) for the third time and starts the T3321 timer (15 seconds) for the third time. Before the T3321 timer expires for the third time, the terminal does not receive a response to the Mo Detach request from the network (2G or 3G network), and the T3321 timer expires three times.

[0103] After the third deregistration attempt fails, the UE initiates a Mo Detach request to the network (2G or 3G network) for the fourth time, starting the T3321 timer (15 seconds) for the fourth time. Before the T3321 timer expires for the fourth time, the terminal does not receive a response to the Mo Detach request from the network (2G or 3G network), and the T3321 timer expires four times.

[0104] After the fourth deregistration attempt fails, the UE initiates a Mo Detach request to the network (2G or 3G network) for the fifth time, starting the T3321 timer (15 seconds) for the fifth time. Before the T3321 timer expires for the fifth time, the terminal does not receive a response to the Mo Detach request from the network (2G or 3G network), and the T3321 timer expires five times.

[0105] After the UE fails in five Mo Detach attempts to register, the following steps S5 to S7 are executed, and the UE starts to initiate a network search to register with a network other than the 2G or 3G network.

[0106] Step S5. According to the protocol, after the T3321 timer times out 5 times, the UE no longer waits for the network response, but directly releases the connection and initiates a new network search registration.

[0107] Link release refers to a terminal releasing the PS domain link with the connected network. This includes closing the communication channel used for data transmission with the connected network and releasing resources used for data transmission (such as IP addresses). Completing link release means the terminal has disconnected the data connection with the connected network.

[0108] Here, the searched new network is taken as an example of a high-standard network such as an LTE network or an NR network. For relevant content about the terminal registering with the high-standard network, refer to the following description of step S6 and step S7.

[0109] S6. The UE initiates a registration request to the higher-standard network.

[0110] The term "high-standard" in "high-standard network" is a relative term, indicating that 4G / 5G networks are higher standards than 2G / 3G networks. This does not mean that high-standard networks can only be 4G / 5G networks. In fact, high-standard networks can be different networks in different scenarios. For example, if the network connected to the terminal is a 2G network, the 3G network is also considered a high-standard network.

[0111] S7. The network accepts the UE registration request.

[0112] The network in step S7 can be a 4G / 5G network (LTE corresponds to 4G network, NR corresponds to 5G network).

[0113] After the network accepts the registration request initiated by the UE, the UE can establish a new data connection with the high-standard network.

[0114] It should be noted that the protocol involved in the aforementioned step S5 includes the 3rd Generation Partnership Project (3GPP) protocol. The 3GPP protocol includes multiple communication standards, such as the aforementioned GSM, WCDMA, LTE, and NR.

[0115] When the network connected to the terminal is a 2G / 3G network, the Mo Detach initiated by the terminal may also be called GRPS Mo Detach (mobile original GPRS detach without switching off).

[0116] In Figure 3, the example of a terminal switching to a higher-standard network after disconnecting from the connected network is provided as an example. In some cases, the terminal may switch to a network with a lower standard than the connected network, or reconnect to the connected network. After disconnecting from the connected network, the network selected is based on factors such as signal strength, availability, and the terminal's network priority settings.

[0117] It should be noted here that Figure 3 is explained using the example of initiating Mo detach (GPRS Mo Detach) to a 2G / 3G network on a standard GSM or WCDMA. In fact, it is not limited to 2G / 3G networks. When the network to which the terminal is connected is a 4G / 5G network, the processing flow for initiating Mo Detach to a 2G / 3G network on a standard LTE or NR is also the process shown in Figure 3, with corresponding modifications. For example, change GSM to LTE, and change WCDMA to NR. When the network to which the terminal is connected is a 4G network, the high-standard network obtained by searching the network can be a 5G network. When the network to which the terminal is connected is a 4G network, the available network obtained by searching the network can be one of the 4G network, 3G network or 2G network.

[0118] Among them, when the network connected to the terminal is a 4G / 5G network, the Mo Detach initiated by the terminal to the connected network can also be called EPS Mo Detach (mobile original EPS detach without switching off).

[0119] As shown in Figure 3, the GPRS Mo Detach process starts simultaneously with the T3321 timer. If the network doesn't respond, the UE will attempt five times, each time counting until the T3321 timer (15 seconds) expires. After five attempts, the UE will stop waiting and proactively complete the GPRS detach process. If the network (2G / 3G network) fails to respond to the UE-initiated GPRS Mo Detach, resulting in multiple T3321 timer expiration, the UE will remain in the deregistration state for a long time (e.g., 15 x 5 = 75 seconds), preventing a quick network handover.

[0120] When 2G and 3G networks are well-established, this process allows the network (2G / 3G network) to quickly respond to UE-initiated Mo Detach requests, minimizing the impact on the UE. However, as 2G / 3G networks are phased out, the inability of the network (2G / 3G network) to respond to UE-initiated GPRS Mo Detach requests, resulting in multiple T3321 timer timeouts, will become increasingly prominent, with the scope and frequency of impact increasing. Therefore, this process is no longer applicable during the current phase of 2G / 3G network phaseout.

[0121] Among them, the performance of the networks that are being phased out (2G / 3G networks) is inferior to that of subsequent networks (such as 4G / 5G networks). For example, the data transmission rate is lower. Therefore, the networks that are being phased out can also be called low-standard networks.

[0122] Based on the above content, it can be known that a low-standard network (such as a 2G / 3G network) encounters a terminal (UE) initiating GPRS Mo Detach to the network on GSM / WCDMA. However, due to network withdrawal, the network coverage is reduced, resulting in a weak signal. Therefore, the low-standard network does not respond to the GPRS Mo Detach initiated by the UE, causing the UE to be in an attempted deregistration state for a long time (for example, 15×5=75), and during this period, the UE cannot try to search and register with other standards, thereby affecting the UE's data service Internet experience and the high-standard network it is stationed on. Referring to Figure 4, there is shown a schematic diagram of a scenario in which the terminal (UE) is unable to deregister with an available network when the low-standard network signal is weak.

[0123] As shown in Figure 4, when the user is on a high-speed train and the train is traveling from high-speed station A to high-speed station B, the terminal will move from area 1 covered by the 4G / 5G network to area 2 covered by the 2G / 3G network. Then it will move from area 2 covered by the 2G / 3G network to area 3 covered by the 4G / 5G network. Corresponding to the scenario in Figure 1, due to the withdrawal of the 2G / 3G network, the coverage area of ​​the 2G / 3G network will be reduced from area B in the example in Figure 1 to area 2 in the example in Figure 4. In area 2, the terminal can display user interface 21 and user interface 22. Referring to the network indicator 113 in user interface 21 and user interface 22, this indicates that the terminal has established a data connection 1 with the 3G network and sent a message 221 through the data connection, which indicates that the 3G network signal to which the terminal is connected is better at this time.

[0124] However, when the terminal leaves area 2 and enters area 3, the network covered by area 3 is a 4G / 5G network, and the terminal cannot complete data transmission using the 3G network. The terminal executes the method shown in Figure 3 above and sends a Mo Detach to the 3G network on the standard WCMDA. However, there is no 3G network in area 3, and the Mo Detach sent cannot get a response from the 3G network. Therefore, the terminal will attempt Mo Detach multiple times, resulting in a long period of trying to register. In area 3 covered by the 4G / 5G network, it cannot switch to the available 4G / 5G network in time, resulting in the terminal being unable to complete data transmission, affecting the user experience.

[0125] Among them, exemplary scenarios where the terminal fails to complete data transmission can refer to user interface 23 - user interface 25. As shown in user interface 23 and user interface 24, when the terminal attempts to send message 281 to another terminal via data connection 1, a loading indicator 111 appears next to the message box. Referring to user interface 24 and user interface 25, the terminal still fails to complete the message sending via data connection 1 within a long period of time (e.g., 18:00 - 18:01), and a "transmission failed" indicator 251 is displayed around the message box for sending message 231 to prompt the user that data transmission cannot be completed.

[0126] In another solution, for the scenario where the UE initiates a Mo Detach to a low - mode network and the low - mode network does not respond to the Mo Detach, resulting in the timeout of the T3321 timer. The number of attempts for the T3321 timer timeout defined in the original protocol (such as the standard GSM or WCDMA) is reduced from x (usually 5) times to y times (0 < y < x), and the duration of the T3321 timer is shortened from h (usually 15) seconds to i seconds (0 < i < h), obtaining the modified network configuration. For example, y = 5, i = 1. That is, after the UE attempts a Mo Detach without response once, it no longer waits for the network response and directly releases the link locally and attempts to search for and register to other modes of networks.

[0127] Compared with the original protocol process (refer to Figure 3), this solution uses the modified network configuration for Mo Detach, significantly shortening the waiting duration for the network not to respond during Mo Detach. The process of this solution is as shown in Figure 5 below (taking y = 1, i = 5 as an example).

[0128] Among them, the low - mode network includes 2G / 3G networks, and the modified network configuration includes network configurations applicable to GSM (corresponding to 2G networks) and / or WCDMA (corresponding to 3G networks).

[0129] As shown in Figure 5, the process for the terminal to initiate Mo Detach in the modified network configuration can refer to the following steps S11 - step S15.

[0130] S11. The UE initiates a Mo Detach to the network and simultaneously starts the T3321 timer (5 seconds). It is expected that the terminal gets a network response (GSM corresponds to 2G networks, WCDMA corresponds to 3G networks) before the T3321 timer times out.

[0131] For the content of this step S11, reference can be made to the description of step S1 above and make appropriate adaptations (such as modifying the time for the T3321 timer to timeout from 15 seconds to 5 seconds).

[0132] S12. While the T3321 timer is in effect, the terminal does not receive a response to the Mo Detach request initiated by the network, causing the T3321 timer to time out once.

[0133] The terminal did not receive a response to the Mo Detach request from the network before the T3321 timer expired. The terminal's first Mo Detach attempt to register failed.

[0134] After the T3321 timer times out once, the UE no longer waits for the network (2G / 3G network) to respond, but directly disconnects and initiates a new network search registration. For details about this process, please refer to the following description of steps S13 to S15.

[0135] The details of chain release can be found in the above description of chain release in step S5, which will not be described in detail here.

[0136] S13. The UE no longer waits for the network response, but directly releases the link locally and initiates a new network search registration.

[0137] Here, we take the searched new network as an example, which is a high-standard network such as LTE (corresponding to 4G network) or NR (corresponding to 5G network).

[0138] S14. The UE initiates a registration request to the higher-standard network.

[0139] S15. The network accepts the UE registration request.

[0140] For the contents of step S14 and step S15, reference may be made to the aforementioned description of step S6 and step S7, which will not be repeated here.

[0141] In this way, compared with the original protocol process (shown in Figure 3), this solution (shown in Figure 5) mainly reduces the number of Mo Detach attempts and can also shorten the waiting time for the network response during Mo Detach, thereby significantly shortening the Mo Detach network unresponsive process, allowing the UE to search for and register with other standard networks more quickly, restore the network more quickly, and bring a better data service experience. Referring to Figure 6, an exemplary scenario of a terminal (UE) quickly locating an available network when the signal of a low-standard network is weak.

[0142] In the scenario shown in Figure 6, the user is on a high-speed train. When the train departs from high-speed railway station A to high-speed railway station B, the terminal will move from area 1 covered by the 4G / 5G network to area 2 covered by the 2G / 3G network. Then it moves from area 2 covered by the 2G / 3G network to area 3 covered by the 4G / 5G network. In area 1, the terminal can be stationed on the 4G / 5G network. When it arrives in area 2, the terminal can be stationed on the 2G / 3G network. In area 2, the user interface involved in the terminal performing data transmission can be user interface 21 and user interface 22. The data transmission process of the terminal in area 2 is the same as the data transmission process in area 2 in Figure 4 above, and will not be repeated here.

[0143] When the terminal leaves area 2 and enters area 3, the network covered by area 3 is a 4G / 5G network, and the terminal cannot complete data transmission using the 3G network. The terminal executes the method shown in Figure 5 above and sends Mo Detach to the 3G network on WCMDA. Even if there is no 3G network in area 3, the Mo Detach sent cannot get a response from the 3G network. However, the number of times the terminal attempts Mo Detach is reduced, and the timer timeout is shortened, which will not cause the terminal to be in an attempt to deregister state for a long time compared to Figure 4. Referring to the user interface 31 in Figure 6, in area 3 covered by the 4G / 5G network, it can switch to the available 4G / 5G network more quickly, so that the terminal completes the transmission of data (message 1411).

[0144] Therefore, based on the above content, it can be seen that the number of verification times is reduced and the timer is shortened, and the terminal can return to the high-standard network more quickly.

[0145] It should also be noted that the process is not limited to the "GPRS detach without switching off" type, which causes the network to be unresponsive after the UE initiates GRPS Mo Detach. As long as the UE's Mo Detach process is entered (including GPRS detach with switching off and EPS detach without switching off initiated by the terminal side), the shortening of the Mo Detach process shown in Figure 5 is also applicable.

[0146] GPRS detach without switching off is the aforementioned GPRS Mo Detach, which occurs when the terminal is connected to a 2G / 3G network. EPS detach without switching off is the aforementioned EPS Mo Detach, which occurs when the terminal is connected to a 4G / 5G network.

[0147] That is to say, although Figure 5 is a shortened Mo Detach (GPRS Mo Detach) process for GSM and WCDMA (GSM corresponds to 2G network, WCDMA corresponds to 3G network). However, the current protocol (3GPP protocol) also has a similar processing flow for EPS Mo Detach under LTE and NR (LTE corresponds to 4G network, NR corresponds to 5G network). Therefore, the present invention is also applicable to LTE and NR (LTE corresponds to 4G network, NR corresponds to 5G network). For example, when a network newer than 4G / 5G network appears in the future, and the 4G network and 5G network need to be gradually decommissioned, the shortened GPRS Mo Detach process shown in Figure 5 can be applied to EPS Mo Detach to achieve the shortened EPS Mo Detach process.

[0148] The following further describes the usage scenarios of the method for shortening the Mo Detach process in the above content using three specific scenarios.

[0149] It should be noted that in the foregoing content, the number of Mo Detach is explicitly shortened to 1 and the T3321 timer duration (timeout period) is explicitly shortened to 5 seconds, but the number and duration can be adjusted according to the actual network deployment and response situation.

[0150] For example, in a usage scenario (usage scenario 1), the network configuration used by the low-standard network in the terminal is a modified network configuration. The modification includes: changing the number of Mo Detach Z (maximum number of attempts) in the standard network configuration to a preset number N (less than the maximum number of attempts), and / or, changing the T3321 timer timeout duration (protocol time) in the standard network configuration to a preset time (less than the protocol time). The standard network configuration can be regarded as a standard protocol. The standard protocol stipulates that the conditions for the terminal to release the PS domain link between the terminal and the connected network include: the deregistration request initiated by the terminal is responded to by the connected network, or the Z deregistration requests initiated by the terminal are not responded.

[0151] In Scenario 1, the terminal initiates N deregistration requests to the connected lower-standard network using the modified network configuration. When the terminal determines that the lower-standard network has not responded to the Nth deregistration request, it releases the PS domain link with the lower-standard network and initiates a network search. If an available network is found, the terminal initiates a registration request to Available Network 1, which establishes a new data connection with Available Network 1.

[0152] For a detailed description of this process, reference may be made to the following description of steps S101 to S107 in FIG. 7 .

[0153] S101. The terminal determines that the low-standard network 1 does not respond to the data service activation request.

[0154] Here, the low-standard network 1 is the low-standard network to which the terminal is connected.

[0155] When the terminal wants to perform data services, it will initiate a data service activation request to the low-mode network 1. If it does not receive a response from the low-mode network 1 to the data service activation request within a certain period of time, the terminal determines that the low-mode network 1 has not responded to the data service activation request.

[0156] In step S101, the reason for the low-standard network 1 data service activation request may include: the low-standard network 1 is de-networking, and the low-standard network 1 number is poor when the terminal initiates the data service activation request, resulting in the low-standard network 1 being unable to respond to the data service activation request.

[0157] It should be noted that step S101 is optional and is not a necessary condition for the terminal to execute step S102. The conditions for the terminal to execute step S102 may also include but are not limited to: the terminal determines that the signal strength of the low-standard network 1 is less than a preset threshold.

[0158] S102. The terminal initiates a PS domain deregistration request to the low-standard network 1 and starts timing at the same time.

[0159] The timing in step S102 may be performed by starting the aforementioned T3321 timer.

[0160] Here, the PS domain deregistration request is the Mo Detach mentioned in the above content.

[0161] Generally speaking, low-standard networks (including low-standard network 1) are currently being phased out (or are in the process of being phased out). Currently, this includes 2G / 3G networks. In the future, if 4G or 5G networks are phased out, they may also be referred to as low-standard networks.

[0162] S103. When the preset time is reached and the terminal does not receive a response from the low-standard network 1 to the PS domain deregistration request, the timeout count is increased by 1. The preset time is less than the agreed time.

[0163] When the T3321 timer is started, the protocol time is the time when the T3321 timer times out.

[0164] It should be noted that step S103 is optional, and the protocol time may not be modified, and only the preset number of times may be modified. The Mo Detach process may also be shortened.

[0165] If the number of timeouts does not reach the preset number, the terminal continues to execute the aforementioned step S102 to initiate a PS domain deregistration request.

[0166] When the timeout times reach the preset times (less than the maximum number of attempts), the terminal executes the following step S104 and no longer waits for the response of the low-standard network 1 to the PS domain deregistration request, directly releases the link and initiates a new network search registration.

[0167] S104. The terminal no longer waits for a response to the PS domain deregistration request, releases the PS domain link with the low-standard network 1 and initiates a network search.

[0168] S105. When an available network is found, the terminal initiates a registration request to the available network 1, where the registration request includes a PS domain registration request.

[0169] The terminal first scans for available networks in the surrounding area. If the number of available networks is greater than two, the terminal may select the best available network (available network 1) from among the multiple available networks based on a network selection strategy (e.g., based on factors such as network priority and network signal strength).

[0170] Then, the terminal initiates a registration request to the available network 1, wherein the registration (combined attach) request includes at least a PS domain registration request. Alternatively, in addition to the PS domain registration, the registration request may also include a CS domain registration request.

[0171] The PS domain registration request is used to request registration with the available network 1 and to establish a new data connection with the available network 1 .

[0172] The CS domain registration request is a request to establish a voice call connection, which is used to fall back from the available network 1 to the low-standard network 1 for voice calls.

[0173] The CS domain registration request may carry context information related to the terminal's registration with the low-standard network 1. This context typically includes the terminal's identification information (such as IMSI, IMEI), access parameters, and connection status in the low-standard network 1. By carrying this context information, the terminal can quickly restore the previously established communication state when switching to the low-standard network 1 for a voice call while connected to the available network 1, thereby providing continuous voice call service.

[0174] It should be noted that, when a registration request includes a PS domain registration request and a CS domain registration request, the registration request may be referred to as a joint registration request.

[0175] Available network 1 here is typically a high-standard network. Because high-standard networks have better performance, when available networks include high-standard networks and other low-standard networks 1 other than the connected network, the terminal is more likely to select the high-standard network based on the network selection strategy. For a description of the high-standard network, please refer to the description of the high-standard network in step S6 above and will not be repeated here.

[0176] However, in some scenarios, the available network 1 may also be a low-standard network other than the connected network. For example, as shown in FIG8 , when the terminal is in an elevator, high-frequency signals (such as 4G / 5G signals) are more easily shielded by materials such as metal than low-frequency signals (2G / 3G signals), and are difficult to penetrate the elevator car (composed of materials such as metal) and enter the elevator. Therefore, the elevator can be covered by a 2G network or a 3G network, and the terminal is usually connected to the 3G network (because it is better than the 2G network). When there are too many users using the 3G network in the elevator, the 3G network signal (a low-standard network 1) will become weak, causing the 3G network to be unable to respond to the data service activation request. Therefore, the terminal can execute S102 and step S104 to release the connection with the 3G network and search for the network. At this time, an available 2G network (another low-standard network) can be searched, and in step S105, the terminal uses the 2G network as the available network 1 and initiates a joint registration request to the 2G network.

[0177] For the scenario where the available network is a high-standard network. After the terminal is connected to the 2G network in the elevator. Referring to Figure 9 again, after walking out of the elevator, the terminal enters the 4G / 5G network coverage area. At this time, the 2G network is unavailable. At time t, after the terminal initiates a PS domain deregistration request to the 2G network for the first time for a preset number of times, if no response to the PS domain deregistration request from the 2G network is received, the connection with the 2G network is released and the network is searched. For example, at this time, an available 5G network (in a high-standard network) can be searched, then in step S105, the terminal uses the 5G network as the available network 1 and initiates a joint registration request to the 5G network.

[0178] S106. The terminal receives a response from the available network 1 to the registration request.

[0179] The response in step S106 indicates that the available network 1 agrees with the joint registration request of the terminal.

[0180] S107. Registration is successful, and the terminal is connected to the PS domain of available network 1.

[0181] Connecting to the PS domain of available network 1 indicates that the terminal has established a new data connection with available network 1.

[0182] The successful joint registration also indicates that the terminal establishes a voice call connection in the available network 1, and the voice call connection is used to fall back from the available network 1 to the low-standard network 1 for voice calls.

[0183] It should be noted that a low-standard network can refer to a network that is being phased out. However, the phase-out of low-standard networks varies across different regions. For example, the phase-out of the same network can vary across different countries. In some regions, low-standard networks are being phased out, while in others, they remain. However, terminals are mobile, meaning they can move from an area where low-standard networks are being phased out to an area where they remain.

[0184] Therefore, in another usage scenario (usage scenario 2), the network configuration corresponding to the low-standard network in the terminal includes both the modified network configuration involved in usage scenario 1 and the network configuration before modification (standard network configuration). In this usage scenario 2, when the terminal determines that the connected low-standard network has not responded to the Nth deregistration request, the terminal releases the PS domain link with the low-standard network and initiates a network search before the terminal also determines that the location belongs to a preset area. The preset area is configured to enable the modified network configuration to initiate a deregistration request to the low-standard network. If the terminal determines that the location does not belong to the preset area, the terminal initiates a deregistration request to the low-standard network N times using the network configuration before modification. After the terminal determines that the low-standard network has not responded to the Nth deregistration request, the terminal will initiate a deregistration request to the low-standard network for the N+1th time. Only after it is determined that the initiated deregistration request is responded to, or that the Zth initiated deregistration request is not responded to, will the terminal release the PS domain link with the low-standard network and initiate a network search. For a detailed description of this process, please refer to the following description of steps S201 to S208 in FIG. 10 .

[0185] S201. The terminal determines that the low-standard network 1 does not respond to the data service activation request, and the low-standard network 1 is configured with a new network standard and an original network standard.

[0186] The new network configuration is the modified network configuration mentioned above, and the original network configuration is the network configuration before the modification mentioned above.

[0187] The process of determining that the low-standard network 1 has not responded to the data service activation request in step S201 is the same as that of the aforementioned step S101. Please refer to the aforementioned description of step S101 and will not be repeated here.

[0188] S202. Determine that the terminal's location belongs to area 1.

[0189] In some possible cases, the terminal may determine area 1 through the area identifier of the connected low-standard network 1.

[0190] S203: Is it configured to enable the new network configuration in area 1?

[0191] In some cases, whether the new network configuration is enabled in different regions is configured in the terminal before it leaves the factory. However, as the network withdrawal situation changes, the status of whether the new network configuration is enabled in each region can be updated.

[0192] In area 1, if low-standard network 1 is disconnected, configure and enable the new network configuration. If no network disconnection occurs, configure and enable the original network configuration.

[0193] If it is configured to enable the new network configuration in area 1, the terminal executes the following step S204a to initiate a PS domain deregistration request to the low-standard network 1 through the new network configuration.

[0194] If it is configured to enable the original network configuration in area 1, the terminal executes the following step S204b to initiate a PS domain deregistration request to the low-standard network 1 through the original network configuration.

[0195] S204a. The terminal initiates a PS domain deregistration request to the low-standard network 1 according to the new network configuration.

[0196] The contents involved in step S204a are the same as those involved in the aforementioned steps S102 to S104. Please refer to the aforementioned relevant contents and do not repeat them here.

[0197] S204b. The terminal initiates a PS domain deregistration request to the low-standard network 1 according to the original network configuration.

[0198] The contents involved in step S204b are the same as those involved in the aforementioned Figure 3. Please refer to the aforementioned description of Figure 3 and related contents, and no further details will be given here.

[0199] S205. The terminal releases the PS domain link with the low-standard network 1 and initiates a network search.

[0200] Step S205 is the same as the process in which the terminal releases the PS domain link with the low-standard network 1 and initiates a network search in the aforementioned step S104. Please refer to the aforementioned description of the relevant content in step S104 and will not be repeated here.

[0201] S206. When an available network is found, the terminal initiates a registration request to the available network 1, where the registration request includes a PS domain registration request.

[0202] S207. The terminal receives a response from the available network 1 to the registration request.

[0203] S208. The terminal is successfully registered and connected to the PS domain of available network 1.

[0204] The contents involved in steps S206 to S208 are respectively the same as those in steps S105 to S107 mentioned above. Please refer to the description of steps S105 to S107 mentioned above and will not be repeated here.

[0205] In another usage scenario (usage scenario 3), not limited to low-standard networks, new network configurations and original network configurations can be configured for all networks supported by the terminal. In addition to determining whether to use the new network configuration based on whether the area to which the terminal belongs is disconnected from the network in usage scenario 2, other conditions other than disconnection can also be used to determine whether to enable the new network configuration. In usage scenario 3, if the network (including low-standard networks and high-standard networks) connected to the area where the terminal is located has not been disconnected, other conditions other than disconnection are used to determine whether to enable the new network configuration to initiate a PS domain deregistration request to the connected network. In the event that the network connected to the area where the terminal is located has been disconnected from the network, the new network configuration is enabled to initiate a PS domain deregistration request to the connected network.

[0206] Among them, other conditions include: whether the network coverage of the network to which the terminal is connected in the area is lower than a preset level. For example, the network coverage of the network to which the terminal is connected in the area is less than the coverage of other networks except the connected network. For example, when the connected network is a 4G network or a 5G network, although the 4G network or the 5G network has not been de-networked, in some remote areas, the coverage of the 4G network or the 5G network is low, lower than that of the 2G / 3G network. Therefore, it can be set at this location to reduce the number of de-registration requests initiated to the 4G network or the 5G network.

[0207] For an exemplary process of the terminal initiating Mo detach in usage scenario 3, reference may be made to the following description of steps S301 to S08.

[0208] S301. The terminal determines that a weak network does not respond to a data service activation request, and a new network configuration and an original network configuration are configured in the weak network.

[0209] The weak network here refers to a network to which the terminal is connected and has a weak signal. The weak network can be a low-standard network or a high-standard network.

[0210] S302: Determine that the terminal is located in area 2 and the weak network has not been disconnected from the network in area 2.

[0211] The method for determining region 2 is the same as the method for determining region 1 in step S102. Whether different regions are de-networked is configured in the terminal before leaving the factory. However, it can be updated later as the de-networking situation changes.

[0212] It should be noted here that if the weak network is disconnected in area 2, the new network protocol can be directly enabled to initiate a PS domain deregistration request to the weak network.

[0213] S303: Whether other conditions for enabling a new network configuration other than disconnecting from the network are met.

[0214] Here, in addition to the network exit, other conditions for enabling the new network configuration may include the weak network having a coverage range below a preset level in the area where the terminal is located. A description of these other conditions can be found in the aforementioned related content and will not be repeated here. The terminal's location can be determined using a global positioning system (GPS).

[0215] If other conditions for enabling the new network configuration except for network exit are met, the terminal executes the following step S304a to initiate a PS domain deregistration request to the weak network through the new network configuration.

[0216] If other conditions for enabling the new network configuration except for network deregistration are not met, the terminal executes the following step S304b to initiate a PS domain deregistration request to the weak network through the original network configuration.

[0217] S304a. The terminal initiates a PS domain deregistration request to the weak network according to the new network configuration.

[0218] S304b. The terminal initiates a PS domain deregistration request to the weak network according to the original network configuration.

[0219] S305. The terminal releases the PS domain link with the weak network and initiates a network search.

[0220] S306. When an available network is found, a registration request is initiated to the available network 1. The joint registration request includes a PS domain registration request.

[0221] When the standard of the weak network is lower than that of the available network, when an available network is found, a joint registration request or a PS domain registration request may be initiated to the available network 1. For the relevant contents of this process, please refer to the aforementioned step S105 or step S206.

[0222] When the weak network standard is higher than the available network standard, when an available network is found, a PS domain registration request is initiated to the available network 1. For details about initiating the PS domain registration request, please refer to the PS domain registration-related details in the aforementioned step S105 or step S206.

[0223] S307. Receive a response from available network 1 to the registration request.

[0224] S308. Registration is successful, and the system is connected to the PS domain of available network 1.

[0225] The contents involved in step S304a, step S304b, and step S305 to step S308 are similar or identical to those in the aforementioned step S204a, step S204b, and step S205 to step S208, respectively.

[0226] It should be noted that step S203 in the aforementioned usage scenario 2 and steps S302 and S303 in the usage scenario 3 describe the method for determining whether the terminal uses the new network configuration or the original network configuration. The terminal needs to determine whether to use the new network configuration or the original network configuration based on the area in which it is located and the nature of the connected network. This includes: when the area in which the terminal is located is a preset area and the network to which it is connected is a preset network, the terminal uses the new network configuration. When the area in which the terminal is located is not a preset area and the network to which it is connected is not a preset network, the terminal uses the original network configuration.

[0227] Among them, the preset area is an area where there is a network withdrawal situation (for example, the area can be divided according to the network withdrawal situation in different countries) or an area where there is no network withdrawal situation, but the network coverage is uneven (for example, it can be divided according to prefecture-level cities smaller than the country). The preset network may include a network whose network quality in the preset area is lower than the preset conditions. The network whose network quality in the preset area is lower than the preset conditions includes a network where there is a network withdrawal situation in the preset area, such as the low-standard network involved in scenario 2. Alternatively, the network whose network quality in the preset area is lower than the preset conditions includes a network whose network coverage in the preset area is lower than a preset level, such as the weak network involved in scenario 3.

[0228] It should also be noted that, as described in Figures 10 and 11 above, the terminal can determine whether to use the new network configuration or the original network configuration before initiating the PS domain deregistration request. However, it can also be performed after initiating N PS domain deregistration requests.

[0229] For example, after connecting to a network (network 1), if a terminal needs to disconnect the data connection with network 1, it can initiate a deregistration request to network 1. If the terminal has already initiated N registration requests, and network 1 does not respond to the Nth deregistration request, and the terminal determines that it is in the preset area and network 1 is the preset network, the terminal releases the PS domain link with network 1 and initiates a network search. If network 2 is found, the terminal initiates a registration request to network 2 to establish a new data connection. In this case, the first N deregistration requests are sent based on the original network configuration.

[0230] If network 1 does not respond to the Nth deregistration request and the terminal is not in the preset area, or if network 1 does not respond to the Nth deregistration request and network 1 is not a preset network standard, the terminal initiates the N+1th deregistration request to network 1. In this case, the first N deregistration requests are sent based on the original network configuration.

[0231] It should also be noted that the terminal starts the T3321 timer after initiating the i-th deregistration request to the network 1, where i is greater than or equal to 1 and less than or equal to N;

[0232] When the T3321 timer reaches a preset duration, the terminal does not receive a response from network 1 to the i-th deregistration request, and i is less than N, the terminal initiates an (i+1)-th deregistration request to network 1.

[0233] When the terminal is in the preset area and network 1 is the preset network format, the preset duration is duration 1. When the terminal is in the preset area, or when network 1 is not the preset network format, the preset duration is duration 2; duration 2 is greater than duration 1, and duration 2 is the duration of the T3321 timer specified in the standard protocol.

[0234] The following describes an exemplary terminal provided in an embodiment of the present application.

[0235] FIG12 is a schematic diagram of the structure of the terminal provided in an embodiment of the present application.

[0236] The following embodiment is specifically described using a terminal as an example. It should be understood that the terminal may have more or fewer components than those shown in FIG12 , may combine two or more components, or may have different component configurations. The various components shown in FIG12 may be implemented in hardware, software, or a combination of hardware and software, including one or more signal processing and / or application-specific integrated circuits.

[0237] The terminal 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 speaker 170A, a receiver 170B, a microphone 170C, an earphone interface 170D, 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. The sensor module 180 may include a pressure sensor 180A, a gyroscope sensor 180B, an air pressure sensor 180C, a magnetic sensor 180D, an acceleration sensor 180E, a distance sensor 180F, a proximity sensor 180G, a fingerprint sensor 180H, a temperature sensor 180J, a touch sensor 180K, an ambient light sensor 180L, a bone conduction sensor 180M, etc. The processor may include an application processor (AP) and a modem processor (also called a baseband processor).

[0238] The aforementioned original network configuration or new network configuration may be recorded in the modem processor.

[0239] It is understood that the structures illustrated in the embodiments of the present application do not constitute specific limitations on the terminal. In other embodiments of the present application, the terminal may include more or fewer components than shown, or may combine or separate certain components, or arrange the components differently. The illustrated components may be implemented in hardware, software, or a combination of software and hardware.

[0240] In the embodiment of the present application, the processor 110 can call the computer instructions stored in the internal memory 121 to enable the terminal to execute the method in the embodiment of the present application.

[0241] The present application also provides a chip system, which includes at least one processor for implementing the functions involved in the method executed by the terminal in any of the above embodiments.

[0242] In one possible design, the chip system further includes a memory, which is used to store program instructions and data, and the memory is located inside or outside the processor.

[0243] The chip system can be composed of chips, or can include chips and other discrete devices.

[0244] Optionally, there may be one or more processors in the chip system. The processor may be implemented in hardware or software. When implemented in hardware, the processor may be a logic circuit, an integrated circuit, etc. When implemented in software, the processor may be a general-purpose processor implemented by reading software code stored in a memory.

[0245] Optionally, the memory in the chip system may be one or more. The memory may be integrated with the processor or may be separated from the processor, which is not limited in the embodiment of the present application.

[0246] Exemplarily, the memory can be a non-transient processor, such as a read-only memory ROM, which can be integrated with the processor on the same chip or can be set on different chips respectively. The embodiments of the present application do not specifically limit the type of memory and the setting method of the memory and the processor.

[0247] Exemplarily, the chip system may be a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), a system on chip (SoC), a central processor unit (CPU), a network processor (NP), a digital signal processor (DSP), a microcontroller unit (MCU), a programmable logic device (PLD) or other integrated chips.

[0248] The present application also provides a computer program product, which includes: a computer program (also referred to as code, or instruction), which, when executed, enables a computer to execute the terminal execution method in any of the above embodiments.

[0249] The present application also provides a computer-readable storage medium storing a computer program (also referred to as code or instruction). When the computer program is executed, the computer executes the method executed by the terminal in any of the above embodiments.

[0250] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

[0251] As used in the above embodiments, the term “when…” may be interpreted to mean “if…” or “after…” or “in response to determining…” or “in response to detecting…”, depending on the context. Similarly, the phrases “upon determining…” or “if (stated condition or event) is detected” may be interpreted to mean “if determining…” or “in response to determining…” or “upon detecting (stated condition or event)” or “in response to detecting (stated condition or event)”, depending on the context.

[0252] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. As used in the specification and appended claims of the present application, the singular expressions "a", "an", "said", "above", "the" and "this" are intended to also include plural expressions unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used in the present application refers to and includes any or all possible combinations of one or more listed items. The symbol " / " used in the present application can represent the meaning of "and / or".

[0253] The terms "first" and "second" are used for descriptive purposes only and should not be understood to imply or suggest relative importance or implicitly indicate the number of the technical features indicated. Therefore, features defined as "first" or "second" may explicitly or implicitly include one or more of such features. In the description of the embodiments of this application, unless otherwise specified, "plurality" means two or more.

[0254] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from one website, computer, server or data center to another website, computer, server or data center via a wired (e.g., coaxial cable, optical fiber, digital subscriber line) or wireless (e.g., infrared, wireless, microwave, etc.) method. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more available media integrations. The available medium can be a magnetic medium (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid-state hard disk).

[0255] Those skilled in the art will appreciate that all or part of the process steps in the above-described method embodiments can be implemented by a computer program instructing the relevant hardware. The program can be stored in a computer-readable storage medium, and when executed, the program can include the process steps in the above-described method embodiments. The aforementioned storage medium includes various media capable of storing program code, such as ROM or random access memory (RAM), magnetic disks, or optical disks.

Claims

1. A network registration method, characterized in that, Including: The terminal sends an Nth deregistration request to the first network, and the deregistration request is used to disconnect the first data connection with the first network. When the first network does not respond to the Nth deregistration request, the terminal is in a preset area, and the first network is a preset network, the terminal releases the packet switched (PS) domain link with the first network and initiates network search; wherein, the PS domain link is used to implement the first data connection; the preset network includes a network with network quality lower than a preset condition in the preset area. When a second network is searched, the terminal sends a registration request to the second network, and the registration request is used to establish a second data connection with the second network. Wherein, N is a positive integer less than Z, and Z is the maximum number of attempts specified in the standard protocol for the terminal to send a deregistration request to the first network. The standard protocol stipulates that the conditions for the terminal to release the PS domain link with the first network include: the deregistration request initiated by the terminal is responded to by the first network, or none of the Z deregistration requests initiated by the terminal are responded to.

2. The method according to claim 1, wherein The network with network quality lower than the preset condition in the preset area includes a network with a network withdrawal situation in the preset area, or the network with network quality lower than the preset condition in the preset area includes a network with a network coverage range lower than a preset level in the preset area.

3. According to claim 1 or 2, characterized in that, The method further includes: When the first network does not respond to the Nth deregistration request and the terminal is not in the preset area, or when the first network does not respond to the Nth deregistration request and the first network is not of the preset network type, the terminal sends an (N + 1)th deregistration request to the first network.

4. The method according to any one of claims 1 to 3, characterized in that, The method further includes: After the terminal sends the ith deregistration request to the first network, it starts the T3321 timer, where i is greater than or equal to 1 and less than or equal to N. When the T3321 timer times out for a preset duration, the terminal does not receive a response from the first network to the ith deregistration request, and i is less than N, the terminal sends an (i + 1)th deregistration request to the first network. When the terminal is in the preset area and the first network is of the preset network type, the preset duration is the first duration; when the terminal is not in the preset area, or when the first network is not the preset network, the preset duration is the second duration; the second duration is greater than the first duration; the second duration is the duration of the T3321 timer specified in the standard protocol.

5. The method according to any one of claims 1-4, characterized in that, The network type of the second network is higher than that of the first network, or the coverage range of the second network in the preset area is greater than that of the first network in the preset area.

6. The method according to claim 4, characterized in that, The second duration is 15 seconds, and the first duration is 5 seconds.

7. The method according to any one of claims 1-6, characterized in that, Z is equal to 5, and N is equal to 1.

8. The method according to any one of claims 1-7, characterized in that, The method further includes: Before the terminal first sends a deregistration request to the first network, the terminal determines that the activation of the data service fails.

9. The method according to any one of claims 1-8, characterized in that, The registration request is further used to establish a voice call connection; the voice call connection is used to fallback from the second network to the first network for voice calls.

10. The method according to any one of claims 1-9, characterized in that the first network is a 2G or 3G network, and the second network is a 4G or 5G network; when the first network is a 2G network, the network mode of the first network includes the Global System for Mobile Communications (GSM) network mode; when the first network is a 3G network, the network mode of the first network includes the Wideband Code Division Multiple Access (WCDMA) network mode.

11. A terminal, characterized in that, comprising: one or more processors and a memory; the memory is coupled to the one or more processors, the memory is used to store computer program code, the computer program code includes computer instructions, and the one or more processors call the computer instructions to cause the terminal to execute the method according to any one of claims 1-10.

12. A chip system, which is applied to a terminal, is characterized in that, The chip system includes one or more processors, and the processors are used to call computer instructions to cause the terminal to execute the method according to any one of claims 1-10.

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