The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 13, 2026
Filed:
Apr. 19, 2023
T-mobile Usa, Inc., Bellevue, WA (US);
Hang Hoi Yau, Sammamish, WA (US);
Christopher Joul, Bellevue, WA (US);
Hyung Keun Choi, Overland Park, KS (US);
Lin Zhang, Overland Park, KS (US);
Syed Hassan Raza, Overland Park, KS (US);
William Hooker, Seattle, WA (US);
Srinivasa Rao Bodapotula, Bellevue, WA (US);
Anthony James Wageman, Lees Summit, MO (US);
T-Mobile USA, Inc., Bellevue, WA (US);
Abstract
Solutions for placing an emergency call over a wireless network improve speed and reliability by prioritizing using an internet protocol (IP) multimedia subsystem (IMS) packet data network (PDN) or protocol data unit (PDU) network (PDN/PDU) over domain reselection when a call attempt fails over an emergency PDN/PDU (EPDN/EPDU). Examples include establishing an IMS PDN/PDU session for a user equipment (UE) over a wireless network; attempting, by the UE, an emergency call using an EPDN/EPDU over the wireless network; and based on at least a failure of the emergency call over the EPDN/EPDU, reattempting the emergency call using the IMS PDN/PDU over the wireless network. Based on at least a failure of the emergency call over the IMS PDN/PDU, the UE performs domain reselection and reattempts the emergency call using a second wireless network. In some examples, wireless networks transmit a network policy for handling the emergency call to the UE.