A terminal device comprising a transceiver, a memory, and a processor is provided. The terminal device may send in a network, an IMS registration request to a network device in the network, and may start an IMS timer corresponding to the network. If the terminal device does not receive a registration accept message from the network device when the IMS timer expires, the terminal device deactivates the network. The network may be one of a first network and a second network, the network device may be one of a first network device and a second network device, and each of the first network and the second network corresponds to an IMS timer with a different duration. In this way, different waiting durations may be provided for IMS registration processes in different networks, to improve user communication experience.