US 12,426,117 B2
Apparatus and method of a mobile terminating user equipment connecting to a fallback network
Yongsheng Shi, Palo Alto, CA (US); Xin Xu, Palo Alto, CA (US); and Jaehyeuk Yang, Palo Alto, CA (US)
Assigned to INNOPEAK TECHNOLOGY, INC., Palo Alto, CA (US)
Filed by INNOPEAK TECHNOLOGY, INC., Palo Alto, CA (US)
Filed on Mar. 30, 2023, as Appl. No. 18/193,251.
Application 18/193,251 is a continuation of application No. PCT/US2021/041493, filed on Jul. 13, 2021.
Claims priority of provisional application 63/085,742, filed on Sep. 30, 2020.
Prior Publication US 2023/0239952 A1, Jul. 27, 2023
Int. Cl. H04L 12/00 (2006.01); H04L 65/1016 (2022.01); H04L 65/1104 (2022.01); H04W 36/00 (2009.01); H04W 76/18 (2018.01)
CPC H04W 76/18 (2018.02) [H04L 65/1016 (2013.01); H04L 65/1104 (2022.05); H04W 36/00226 (2023.05)] 20 Claims
OG exemplary drawing
 
1. An apparatus for wireless communication of a user equipment (UE), comprising:
a memory; and
at least one processor coupled to the memory and configured to:
receive, from a new radio (NR) base station, a paging signal associated with a mobile terminating (MT) internet protocol (IP) multimedia subsystem (IMS) voice session;
send, to the NR base station, a first session initiation protocol (SIP) message in response to the paging signal;
receive, from the NR base station, a second SIP message indicating a SIP failure;
determine that the second SIP message indicates a network failure or a global failure; and
establish a connection with a different radio access technology (RAT) network in response to determining that the second SIP message indicates a network failure or a global failure;
wherein the at least one processor is further configured to:
increment a counter associated with a number of SIP failures when the second SIP message is received; and
bar the UE from performing NR communication for a period, in response to each increment to the counter.