US 11,963,060 B2
WLAN to cellular handover techniques for voice calls
Yifan Zhu, San Jose, CA (US); Vijay Venkataraman, San Jose, CA (US); Viswanath Nagarajan, San Jose, CA (US); Sang Ho Baek, Palo Alto, CA (US); Lakshmi N. Kavuri, Cupertino, CA (US); Utkarsh Kumar, Fremont, CA (US); Krisztian Kiss, Hayward, CA (US); Shivani Suresh Babu, San Jose, CA (US); and Srinivasan Nimmala, San Jose, CA (US)
Assigned to Apple Inc., Cupertino, CA (US)
Filed by Apple Inc., Cupertino, CA (US)
Filed on Oct. 4, 2022, as Appl. No. 17/959,957.
Application 17/959,957 is a continuation of application No. 17/023,173, filed on Sep. 16, 2020, granted, now 11,503,527.
Claims priority of provisional application 62/909,960, filed on Oct. 3, 2019.
Prior Publication US 2023/0023828 A1, Jan. 26, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. H04W 36/14 (2009.01); H04B 17/318 (2015.01); H04L 43/0829 (2022.01); H04L 65/1016 (2022.01); H04L 65/1073 (2022.01); H04W 36/30 (2009.01); H04W 84/04 (2009.01); H04W 84/12 (2009.01)
CPC H04W 36/30 (2013.01) [H04B 17/318 (2015.01); H04L 43/0829 (2013.01); H04L 65/1016 (2013.01); H04L 65/1073 (2013.01); H04W 36/14 (2013.01); H04W 84/042 (2013.01); H04W 84/12 (2013.01)] 26 Claims
OG exemplary drawing
 
1. A method, comprising:
performing, over a wireless local area network, an IP multimedia subsystem (IMS) registration via a non-3GPP interworking function (N3IWF) or evolved packet data gateway (ePDG);
establishing connection over one or more of a first 3GPP network and a second 3GPP network;
determining that the first 3GPP network:
does not support voice communications for a device; or
supports only fallback to the second 3GPP network for voice communications;
originating or receiving a voice call via the N3IWF or ePDG;
disabling a capability associated with the first 3GPP network based on one of:
(a) IMS registration via the N3IWF or ePDG; or
(b) originating or receiving a voice call via the N3IWF or ePDG;
handing over the voice call from the wireless local area network directly to the second 3GPP network using a second 3GPP cellular radio access technology (RAT) in response to disabling the capability associated with the first 3GPP network; and
enabling the capability associated with the first 3GPP network based on one of:
(a) IMS deregistration via the N3IWF or ePDG; or
(b) ending of the voice call.