Patent ID: 9622206
Date: 2017-04-11
CPC Classifications: H04L,H04W

Claim:
1. A method comprising: registering by a user equipment device (UE) with a first radio access network (RAN) that provides connectivity with a transport network; once the UE is thereby registered with the first RAN, registering by the UE, via the first RAN and transport network, with a call server; and in response to registering by the UE with the call server, but before the UE then engages in any calls served by the call server, registering by the UE, via the first RAN, with a second RAN, wherein registering by the UE via the first RAN with the second RAN in response to registering by the UE with the call server comprises, in response to registering by the UE with the call server, transmitting by the UE wirelessly to the first RAN a second-RAN registration request message for forwarding by the first RAN to the second RAN.