US 12,238,626 B2
Enhancements on emergency call handling during a de-registration or detach procedure
Marko Niemi, Oulu (FI); and Matti Moisanen, Oulu (FI)
Assigned to MEDIATEK SINGAPORE PTE. LTD., Singapore (SG)
Filed by MediaTek Singapore Pte. Ltd., Singapore (SG)
Filed on Feb. 23, 2022, as Appl. No. 17/678,255.
Claims priority of provisional application 63/166,274, filed on Mar. 26, 2021.
Prior Publication US 2022/0312171 A1, Sep. 29, 2022
Int. Cl. H04W 4/90 (2018.01); H04W 60/06 (2009.01)
CPC H04W 4/90 (2018.02) [H04W 60/06 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A method, executed by a User Equipment (UE), comprising:
initiating a Mobility Management (MM) de-registration procedure or an MM detach procedure with a mobile communication network;
initiating an emergency call before the MM de-registration procedure or the MM detach procedure has been completed;
aborting the MM de-registration procedure or the MM detach procedure and performing local de-registration or local detach in response to the initiation of the emergency call; and
initiating a registration procedure or an attach procedure after the local de-registration or the local detach;
wherein the emergency call requests an emergency service fallback or a Circuit Switched Fallback (CSFB), or requests establishment of an emergency Protocol Data Unit (PDU) session or an emergency Packet Data Network (PDN) connection;
wherein the method further comprises:
starting a timer upon the initiation of the MM de-registration procedure or the MM detach procedure;
wherein the emergency call is initiated when the timer is running, and the abortion of the MM de-registration procedure or the MM detach procedure is performed.