Patent ID: 9392497
Filing Date: 2016-07-12
CPC Classification: H04W

Claim Text:
1. Network apparatus for Long Term Evolution (LTE) support for calls using circuit-switch fallback (CSFallback), the apparatus comprising: a visited side signaling output configured to provide visited side signaling to respond to a mobile terminated call to a mobile handset supporting LTE by paging said mobile handset and causing said mobile handset to provide a location update via an mobile switching center (MSC), then finding the MSC based on location update signaling, the MSC thus being identified as currently serving said mobile handset, said visited side signaling comprising an emulation of home location register (HLR) signaling for locating said mobile handset and said MSC; and a home side signaling output, configured to provide home side signaling to an HLR associated with said mobile handset, said signaling comprising an emulation of signaling from a serving MSC; wherein said apparatus is configured to transfer said mobile terminated call for handling by said identified currently serving MSC; wherein said mobile handset is roaming in a network other than the network hosting the corresponding home location register, the visited side signaling output being configured to provide one of the group consisting of: signals to initially forward said mobile terminated call to a known MSC, and subsequently, if said known MSC is found to be other than said currently serving MSC, to forward control of said mobile terminated call from said known MSC to said currently serving MSC, or a roaming number request to a currently known serving visitor location register (VLR) and to forward a call thereto, and in the event of a location update coming from said telephone handset arriving via a different VLR, sending a cancel signal to said currently known serving VLR to retrieve said call, and cause said currently known VLR to communicate with said different VLR, said apparatus then configured to forward said call to said different VLR.