Voice rat selection in multi-SIM devices

A wireless communication device, comprising:

• multiple Subscriber Identity Modules (SIMs) in which a first SIM is associated with an Internet Protocol (IP) Multimedia Subsystem (IMS) subscription used for IMS services;
• a memory;
• a processor coupled to the multiple SIMs and the memory, the processor configured to:
• attach the IMS subscription to a first cell of a packet-switched cellular network;
• determine a cause of IMS voice service being not currently available at the IMS subscription, wherein determining the cause of IMS voice service being not currently available comprises determining that Voice over Packet-switched Session (VoPS) is disabled by the first cell;
• bar a Tracking Area Identifier (TAI) associated with the first cell for a period of time;
• determine availability of a wireless local area network (WLAN) connection at the IMS subscription;
• and
• provide voice service at the IMS subscription based on the cause of IMS voice service being not currently available and the availability of the WLAN connection at the IMS subscription.

A method for a wireless communication device having multiple Subscriber Identity Modules (SIMs) in which a first SIM is associated with an Internet Protocol (IP) Multimedia Subsystem (IMS) subscription used for IMS service, the method comprising:

• attaching the IMS subscription to a first cell of a packet-switched cellular network;
• determining a cause of IMS voice service being not currently available at the IMS subscription, wherein determining the cause of IMS voice service being not currently available comprises determining that Service Specific Access Control (SSAC) barring for VoLTE call is enabled at the IMS subscription;
• determining whether a duration of the SSAC barring is greater than a time threshold;
• determining availability of a wireless local area network (WLAN) connection at the IMS subscription;
• and
• providing voice service at the IMS subscription based on whether the duration of the SSAC barring is greater than the time threshold and the availability of the WLAN connection at the IMS subscription.