Wi-Fi Calling Using SIP-IMS Handset and Evolved Packet Data Gateway

摘要

Wi-Fi calling using a mobile device and an evolved packet data gateway (ePDG) is described herein. For example, a mobile device may determine whether any LTE coverage is available, whether data roaming is available, whether a visited public land mobile network (VPLMN) is available, and whether a DNS query to a visited ePDG (VePDG) is successful. The mobile device may connect to the VePDG responsive to a determination that LTE coverage is available, that data roaming is available, that a VPLMN is available, and that the DNS query to the VePDG is successful. Otherwise, the mobile device may connect to a home ePDG (HePDG).

主权项

1. A method of Wi-Fi calling, comprising:
determining, by a mobile device, whether any Long-Term Evolution (LTE) coverage is available; determining, by the mobile device, whether data roaming is available; determining, by the mobile device, whether a visited public land mobile network (VPLMN) is available; determining, by the mobile device, whether a domain name server (DNS) query to a first evolved packet data gateway (ePDG) is successful; connecting to the first ePDG responsive to a determination that LTE coverage is available, a determination that data roaming is available, a determination that a VPLMN is available, and a determination that the DNS query to the first ePDG is successful; and connecting to a second ePDG responsive to a determination that no LTE coverage is available, a determination that no data roaming is available, a determination that no VPLMN is available, or a determination that the DNS query to the first PDG is unsuccessful.