US 10,485,050 B2
Methods and user equipment for managing internet protocol multimedia subsystem call over long-term evolution in single radio voice call continuity area
Srinivas Chinthalapudi, Bangalore (IN); Prasad Basavaraj Dandra, Bangalore (IN); Manan Dixit, Bangalore (IN); and Kedar Santosh Kumar Aalla, Bangalore (IN)
Assigned to Samsung Electronics Co., Ltd., Gyeonggi-do (KR)
Filed by Samsung Electronics Co., Ltd., Suwon-si, Gyeonggi-do (KR)
Filed on Mar. 22, 2017, as Appl. No. 15/466,096.
Claims priority of application No. 201641030564 (IN), filed on Sep. 7, 2016.
Prior Publication US 2018/0070402 A1, Mar. 8, 2018
Int. Cl. H04W 76/25 (2018.01); H04L 29/06 (2006.01); H04W 76/38 (2018.01); H04W 76/27 (2018.01)
CPC H04W 76/25 (2018.02) [H04L 65/1016 (2013.01); H04L 65/1073 (2013.01); H04L 65/1083 (2013.01); H04L 65/80 (2013.01); H04W 76/27 (2018.02); H04W 76/38 (2018.02)] 20 Claims
OG exemplary drawing
 
1. A method for managing an IP multimedia subsystem (IMS) call over Long-Term Evolution (LTE) in a Single Radio Voice Call Continuity (SRVCC) area, the method comprising:
first detecting, by a User Equipment (UE), 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;
initiating, by the UE, a session alert refresh timer with a first value less than a second value of a data inactivity timer from a network entity;
second detecting, by the UE, whether the session alert refresh timer has expired before establishing the IMS call over LTE;
restarting, by the UE, the session alert refresh timer in response to a result of the second detecting indicating that the session alert refresh timer has expired before establishing the IMS call over LTE;
sending, by the UE, a Session Initiation Protocol (SIP) message to the network entity; and
determining, by the UE, whether a caller tune or media pre-configured prior to the IMS call being answered is configured between the first detecting and the initiating,
wherein the initiating a session alert refresh timer is performed in response to the caller tune or the media being configured,
stopping of the session alert refresh timer is performed in response to the caller tune or the media being not configured, and
the method keeps the UE in an RRC connected state by performing the restarting and the sending.