US Patent 11197206 De-configuring of dual-connectivity service to facilitate voice call continuity

When a UE is served with dual-connectivity by a master node (MN) over master connection on a first radio access technology (RAT) and a secondary node (SN) over a secondary connection on a second RAT and where the UE is engaged in a voice call over the master connection, an entity detects that quality of the UE's master connection has become threshold poor and responsively carries out a sequence of operations including (i) releasing the UE's secondary connection with the SN so as to transition the UE from dual-connectivity to standalone-connectivity served by the MN, and (ii) then transferring the UE's voice call from being served by the MN on the first RAT to instead being served by a tertiary node (TN) on a third RAT.