Paging method and apparatus for called terminal

A chip system, comprising:

• one or more interface circuits;
• and
• one or more processors, wherein the one or more interface circuits and the one or more processors are connected to each other through lines;
• wherein the chip system is applicable to a called terminal device comprising a communication device and a memory, wherein the one or more interface circuits are configured to receive signals from the memory and send the signals to the one or more processors, wherein the signals comprise computer instructions stored in the memory, and when the one or more processors execute the computer instructions, the called terminal device is configured to perform:
• receiving a paging message, wherein the called terminal device camps on a 5th generation mobile communication system standalone (5G SA) network;
• starting a first timer based on detecting that a data radio bearer (DRB) for transmitting internet protocol multimedia subsystem (IMS) data is established, and detecting whether the IMS data is received in an on period of the first timer;
• and
• performing fallback to a long term evolution (LTE) network to receive an incoming call based on the first timer expiring and the called terminal device not receiving the IMS data in the on period of the first timer.

The chip system according to claim 11,

• wherein a duration of the second timer is configurable based on a preset parameter;
• and
• wherein the preset parameter comprises at least one of:
• a parameter indicating that the called terminal device is in a screen on state or a screen off state, a network type of the called terminal device, a parameter indicating whether the called terminal device is connected to a wireless fidelity (Wi-Fi) network, an operating mode of the called terminal device, a current traffic used by the called terminal device, or a number of applications simultaneously run on the called terminal device.

An terminal device, comprising:

• a memory storing program instructions;
• and
• a processor coupled to the memory, wherein when the program instructions are executed by the processor, the terminal device is enabled to perform operations comprising:
• receiving a paging message, wherein the called terminal device camps on a 5th generation mobile communication system standalone (5G SA) network;
• starting a first timer based on detecting that a data radio bearer (DRB) for transmitting internet protocol multimedia subsystem (IMS) data is established, and detecting whether the IMS data is received in an on period of the first timer;
• and
• performing fallback to a long term evolution (LTE) network to receive an incoming call based on the first timer expiring and the called terminal device not receiving the IMS data in the on period of the first timer.