Methods and systems for providing call continuity in a user equipment (UE)

A user equipment for providing call continuity in a wireless communication system, wherein the user equipment comprising:

• a memory configured to store computer-readable instructions for providing the call continuity during a call;
• and
• at least one processor, which when executing the computer-readable instructions, configured to:
• detect an occurrence of an event during the call, wherein the event comprises one of:
• a reception of a radio resource control connection release message with a cause as directed signaling connection re-establishment from a drift radio network controller, or
• lack of a reception of response from the drift radio network controller after the user equipment carries out a maximum quantity of allowed cell update attempts for re-establishing the call;
• and
• perform at least one action in response to detecting the occurrence of the event.

A mobile device comprising:

• a memory configured to store computer-readable instructions;
• and
• at least one processor configured to execute the computer-readable instructions, which when executed cause the at least one processor to implement a method of maintaining call continuity during a call while the mobile device travels through one or more areas serviced by a wireless network, the method comprising:
• (a1) detecting that a time elapsed from receipt of a last received acknowledgement message from a serving radio network controller of the wireless network to which the mobile device is connected during the call exceeds a first time duration, and
• (a2) initiating radio link failure procedure prior to a reception of a radio resource control connection release message from the serving radio network controller, in response to detecting that the time elapsed from the receipt of the last received acknowledgement message from the serving radio network controller of the wireless network to which the mobile device is connected exceeds the first time duration;
• (b1) detecting the reception of the radio resource control connection release message from a drift radio network controller indicating a cause of the radio resource control connection release message as directed signaling connection re-establishment, and
• (b2) reselecting a cell of the serving radio network controller and retrying a cell update to re-establish the call, in response to detecting the reception of the radio resource control connection release message from the drift radio network controller indicating the cause of the radio resource control connection release message as directed signaling connection re-establishment;
• and
• (c1) detecting an absence of confirmation from the drift radio network controller of a maximum quantity of allowed cell update attempts for re-establishing the call, and
• (c2) reselecting the cell of the serving radio network controller and retrying the cell update to re-establish the call based on a circuit switched domain re-establishment timer being running, in response to detecting the absence of confirmation from the drift radio network controller of the maximum quantity of allowed cell update attempts for re-establishing the call.