US 12,483,938 B2
Call network switching method and device, and memory
Xiaodong Huang, Guangdong (CN)
Assigned to HUIZHOU TCL MOBILE COMMUNICATION CO., LTD, Guangdong (CN)
Filed by HUIZHOU TCL MOBILE COMMUNICATION CO., LTD, Guangdong (CN)
Filed on Jun. 20, 2022, as Appl. No. 17/807,790.
Application 17/807,790 is a continuation of application No. PCT/CN2020/075994, filed on Feb. 20, 2020.
Claims priority of application No. 201911323228.3 (CN), filed on Dec. 20, 2019.
Prior Publication US 2022/0322158 A1, Oct. 6, 2022
Int. Cl. H04W 36/00 (2009.01); H04W 36/34 (2009.01); H04W 60/00 (2009.01); H04W 36/14 (2009.01); H04W 80/04 (2009.01)
CPC H04W 36/0005 (2013.01) [H04W 36/34 (2013.01); H04W 60/00 (2013.01); H04W 36/1446 (2023.05); H04W 80/04 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A switching method of a communication network, the switching method comprising:
when a mobile terminal needs to be switched from a first communication network to a second communication network, detecting whether the mobile terminal is in a ringing state;
upon a condition that the mobile terminal is in the ringing state, detecting whether the mobile terminal is switched from the ringing state into a connecting state within a predetermined time period; and
upon a condition that the mobile terminal is switched from the ringing state into the connecting state within the predetermined time period, performing an IP Multimedia Subsystem (IMS) registration through the second communication network to connect the mobile terminal to the second communication network;
wherein when the mobile terminal is detected to be in the ringing state, a timer is automatically activated, and the predetermined time period is selected based on a possibility that a called party answers a call;
wherein if the mobile terminal receives a connection information sent by the called party, a call state of the mobile terminal has transitioned from the ringing state to a connected state, and the timer is stopped; if the mobile terminal does not receive the connection information from the called party and also does not receive a termination information, the mobile terminal is still in the ringing state;
wherein the mobile terminal initiates a dialing request to connect to the called party, and when the called party receives a connection request sent by the mobile terminal, the called party feeds back a ringing information, indicating that the mobile terminal is in a ringing state; when the mobile terminal is not in the ringing state, the mobile terminal is directly switched by sending a registration request to an IMS core network via the second communication network based on a connection channel between the mobile terminal and the IMS core network, and upon successful IMS registration, the mobile terminal is connected to the second communication network to accomplish switching of the mobile terminal from the first communication network to the second communication network.