Methods and user equipment for managing internet protocol multimedia subsystem call over long-term evolution in single radio voice call continuity area

A User Equipment (UE) for managing an IP multimedia subsystem (IMS) call over Long-Term Evolution (LTE) in a Single Radio Voice Call Continuity (SRVCC) area, the UE comprising:

• an IMS client including at least one first processor, the at least one first processor configured to,
• first detect whether the IMS call over LTE is in an alert state and whether a Radio Resource Control (RRC) connection is configured for the IMS call over LTE,
• initiate a session alert refresh timer with a first value less than a second value of a data inactivity timer,
• second detect whether the session alert refresh timer has expired before establishing the IMS call over LTE,
• restart the session alert refresh timer in response to a detected result indicating that the session alert refresh timer has expired before establishing the IMS call over LTE,
• send a Session Initiation Protocol (SIP) message to a network entity, and
• determine, by the UE, whether a caller tune or media pre-configured prior to the IMS call being answered is configured between the first detecting operation of the at least one first processor and the initiating operation of the at least one first processor,
• wherein the at least one first processor is configured to initiate the session alert refresh timer in response to the caller tune or the media being configured,
• the at least one first processor is configured to stop the session alert refresh timer in response to the caller tune or the media being not configured, and
• the at least one first processor is configured to keep the UE in an RRC connected state by being configured to restart the session alert refresh timer and send the SIP message to the network entity.