| 摘要 |
Provided are a terminal device, a network device, and an operation method thereof capable of allowing the smooth operation of a VoLTE service even when an IMS PDN used to provide the VoLTE service does not work properly by additionally operating a sub application apart from a main application for the VoLTE service used in a terminal device considering the limitation that one application can use one PDN, that is, one IP only in order to empower the terminal device to connect multi PDN, a multi session including a first session and a second session via single packet network (e.g. an LTE network) and to receive at least some of the VoLTE data packets receiving through the first session with the second session as well. |
