Abstract: A frequency band control method in an abnormal scenario of a dual-card terminal and a terminal device. For a dual-card user scenario that supports a 5G SA mode or a 5G NSA mode, it is determined whether a frequency band combination of two cards belongs to a preset frequency band combination and whether signal quality of a primary card and/or signal quality of a secondary card meet/meets a preset threshold. If the frequency band combination of the two cards belongs to the preset frequency band combination and the signal quality of the primary card and/or the signal quality of the secondary card are/is less than the preset threshold, an NR capability of a terminal device is controlled to fall back, for example, an SA capability is disabled, or an NR link in an ENDC link is released, to improve the signal quality of the two cards.

Abstract: Embodiments of this application provide a method for selecting a network, applied to an electronic device, the method including: receiving a redirect message, where the redirect message carries information about a first frequency: selecting, based on a signal parameter of the first frequency and a signal parameter of a prior frequency, a target frequency from the first frequency and the prior frequency; and redirecting to a cell at the target frequency. It can be seen that after receiving the redirect message, the electronic device selects, based on the signal parameter of the frequency carried in the redirect message and the signal parameter of the prior frequency, the target frequency to be redirected to. Compared with a manner of redirecting to a cell at the frequency carried in the redirect message, the method is more conducive to selecting a frequency at which a signal is better, and further redirecting to a network in which a signal is better.

Abstract: A cell reselection method and apparatus are provided in embodiments of this application. The cell reselection method includes: A terminal selects at least one piece of target prior frequency information from a plurality of pieces of prior frequency information, performs measurement and reselection evaluation based on the target prior frequency information, and performs cell reselection based on a reselection evaluation result.

Abstract: A network search method includes receiving, by a terminal device, a user operation, where the user operation requests communication with a network device by using a 5th Generation (5G) access technology; and when a cell with which the terminal device currently registers is a non-allowed area, searching for a second cell, where the second cell is an allowed area, so that the terminal device communicates with the network device in the second cell by using the 5G access technology. Therefore, when actively initiating a service, the terminal device in the non-allowed area may actively search for a cell that is an allowed area, to communicate with the network device by using the 5G access technology.

Abstract: A method for transfer between communications systems includes establishing at least one first data connection channel in a first communications system, selecting at least one second data connection channel from the at least one first data connection channel, where the second data connection channel is included in the first data connection channel and is certain to support transfer from the first communications system to a second communications system or is uncertain whether to support transfer from the first communications system to the second communications system, and transferring the second data connection channel to the second communications system when the terminal device has been transferred from the first communications system to the second communications system.

Abstract: A method includes: obtaining a first geographical location in which UE is currently located; according to a correspondence between a geographical location and network information of a communications network, determining at least one second geographical location that, relative to the first geographical location, meets a preset proximity condition, and determining network information of at least one second communications network corresponding to each second geographical location; and performing network reselection processing based on at least the network information of the at least one second communications network corresponding to each second geographical location.

Abstract: This application provides a frequency band control method in an abnormal scenario of a dual-card terminal and a terminal device, and relates to the field of communications technologies. In solutions of this application, for a dual-card user scenario that supports a 5G SA mode or a 5G NSA mode, it is determined whether a frequency band combination of two cards is in a blacklist and whether signal quality of a primary card and/or signal quality of a secondary card meet/meets a preset threshold. If the frequency band combination of the two cards is in the blacklist and the signal quality of the primary card and/or the signal quality of the secondary card are/is less than the preset threshold, an NR capability of a terminal device is controlled to fall back, for example, an SA capability is disabled, or an NR link in an ENDC link is released, to improve the signal quality of the two cards.

Abstract: Embodiments of this application relate to the field of electronic technologies, and provide a network icon display method and a terminal, so that display of a 5G network icon can be more consistent with an actual network status of a terminal, a quantity of times of switching of a network icon can be reduced, and user experience can be improved. A specific solution is as follows: An NR SCG is added to a terminal after the terminal registers with a first cell for the first cell, where the first cell is a long term evolution LTE cell. The terminal registers with the first cell for the second time, where an interval between a time point of registering with the first cell for the second time and a time point of registering with the first cell for the first time is less than or equal to preset duration T. The terminal displays a 5G network icon. Embodiments of this application are used to display a network icon.

Abstract: This application provides a method for returning from a low-standard network to a high-standard network, to resolve a problem that a primary card of a terminal device in dual SIM dual standby single pass mode cannot return to the high-standard network after falling back from the high-standard network to the low-standard network during a data service. The method includes: detecting that a first subscriber identification module SIM card of the terminal device falls back from a first-standard network to a second-standard network; obtaining a registration status of a second SIM card, where the registration status includes an operator of the second SIM card and a network on which the second SIM card camps, and the first SIM card and the second SIM card enable the terminal device to work in the dual SIM dual standby single pass mode; obtaining a target standard network based on the registration status of the second SIM card; and registering the first SIM card with the target standard network.

Abstract: A data link quality-based offloading method in dual connectivity includes determining a quality of a bearer link on a user equipment UE side by determining and setting, determining a quality of a radio link by parameters or conditions such as timing advance (TA) timeout, a bit error rate, a signal strength or a signal amplitude, a threshold of continuous scheduling request (SR) sending, a radio link control (RLC) sliding window, a T310 timer, and a triggering of a beam failure recovery process, selecting, based on a determining result, a manner such as a packet replication or selecting a link, and transmitting data through two links.

Abstract: A network search method includes presetting, by a terminal device, a Public Land Mobile Network (PLMN) and a networking mode associated with the PLMN, searching, by the terminal device based on a geographical location to obtain PLMN information of a current geographical location, determining, by the terminal device based on the preset PLMN and the networking mode associated with the PLMN, a current networking mode of the terminal device, and switching, by the terminal device, the networking mode based on a geographical location, signal strength, and a system message.

Abstract: A network search method includes receiving, by a terminal device, a user operation, where the user operation requests communication with a network device by using a 5th Generation (5G) access technology; and when a cell with which the terminal device currently registers is a non-allowed area, searching for a second cell, where the second cell is an allowed area, so that the terminal device communicates with the network device in the second cell by using the 5G access technology. Therefore, when actively initiating a service, the terminal device in the non-allowed area may actively search for a cell that is an allowed area, to communicate with the network device by using the 5G access technology.

Abstract: A method for transfer between communications systems includes establishing at least one first data connection channel in a first communications system, selecting at least one second data connection channel from the at least one first data connection channel, where the second data connection channel is included in the first data connection channel and is certain to support transfer from the first communications system to a second communications system or is uncertain whether to support transfer from the first communications system to the second communications system, and transferring the second data connection channel to the second communications system when the terminal device has been transferred from the first communications system to the second communications system.

Abstract: A switching method and a terminal device, which relate to the communications field. The switching method comprises: establishing, by a terminal device, a first packet data network PDN connection in a long term evolution LTE access network; switching, by the terminal device, the first PDN connection from the LTE access network to a wireless local area network WLAN access network; establishing, by the terminal device, a second PDN connection in the LTE access network, so that the terminal device is in a registered state in the LTE network; and switching, by the terminal device, the first PDN connection or a third PDN connection established in the WLAN access network, to the LTE access network.

Abstract: A method includes: obtaining a first geographical location in which UE is currently located; according to a correspondence between a geographical location and network information of a communications network, determining at least one second geographical location that, relative to the first geographical location, meets a preset proximity condition, and determining network information of at least one second communications network corresponding to each second geographical location; and performing network reselection processing based on at least the network information of the at least one second communications network corresponding to each second geographical location.

Abstract: A network search method includes presetting, by a terminal device, a Public Land Mobile Network (PLMN) and a networking mode associated with the PLMN, searching, by the terminal device based on a geographical location to obtain PLMN information of a current geographical location, determining, by the terminal device based on the preset PLMN and the networking mode associated with the PLMN, a current networking mode of the terminal device, and switching, by the terminal device, the networking mode based on a geographical location, signal strength, and a system message.

Abstract: A communication method includes receiving, by a terminal device, parameter information of m Public Land Mobile Networks (PLMNs), where parameter information of each of the m PLMNs includes fifth generation (5G) parameter information, where each piece of the 5G parameter information includes first information, and the first information indicates a 5G networking architecture supported by a corresponding PLMN, and determining, by the terminal device based on the first information and a 5G networking architecture supported by the terminal device, 5G parameter information of n PLMNs to be stored by the terminal device.

Abstract: A data link quality-based offloading method in dual connectivity includes determining a quality of a bearer link on a user equipment UE side by determining and setting, determining a quality of a radio link by parameters or conditions such as timing advance (TA) timeout, a bit error rate, a signal strength or a signal amplitude, a threshold of continuous scheduling request (SR) sending, a radio link control (RLC) sliding window, a T310 timer, and a triggering of a beam failure recovery process, selecting, based on a determining result, a manner such as a packet replication or selecting a link, and transmitting data through two links.

Abstract: This application provides a method for returning from a low-standard network to a high-standard network, to resolve a problem that a primary card of a terminal device in dual SIM dual standby single pass mode cannot return to the high-standard network after falling back from the high-standard network to the low-standard network during a data service. The method includes: detecting that a first subscriber identification module SIM card of the terminal device falls back from a first-standard network to a second-standard network; obtaining a registration status of a second SIM card, where the registration status includes an operator of the second SIM card and a network on which the second SIM card camps, and the first SIM card and the second SIM card enable the terminal device to work in the dual SIM dual standby single pass mode; obtaining a target standard network based on the registration status of the second SIM card; and registering the first SIM card with the target standard network.

Abstract: A switching method and a terminal device, which relate to the communications field. The switching method comprises: establishing, by a terminal device, a first packet data network PDN connection in a long term evolution LTE access network; switching, by the terminal device, the first PDN connection from the LTE access network to a wireless local area network WLAN access network; establishing, by the terminal device, a second PDN connection in the LTE access network, so that the terminal device is in a registered state in the LTE network; and switching, by the terminal device, the first PDN connection or a third PDN connection established in the WLAN access network, to the LTE access network.