Control of connectivity for a voice-capable UE that will be served by a node that does not support voice-over-packet service

A method for controlling connectivity of a user equipment device (UE), the method comprising:

• detecting handover of the UE from a source master node (MN) that supports voice-over-packet (VOP) service of the UE to a target MN that does not support VOP service of the UE;
• and
• responsive to at least the detecting, causing the target MN to provide the UE with single-connectivity wireless-packet-data service over a master connection between the UE and the target MN rather providing the UE with dual-connectivity wireless-packet-data service over (i) the master connection between the UE and the target MN and (ii) a secondary connection between the UE and a secondary node (SN) that would engage in control-plane signaling with the UE over the master connection,
• wherein the method is carried out by the target MN, and wherein causing the target MN to provide the UE with single-connectivity wireless-packet-data service rather providing the UE with dual-connectivity wireless-packet-data service comprises causing the target MN to forgo adding the secondary connection for the UE or to tear down the secondary connection if the secondary connection is already set up.

A master node (MN) configured to control connectivity of a user equipment device (UE), the MN comprising:

• a wireless communication interface configured to engage in wireless communication with the UE;
• a backhaul network interface through to communicate with other entities;
• and
• a controller configured to cause the MN to carry out operations including:
• (a) detecting (i) that a UE will be served with wireless packet-data service by the MN over a master connection between the UE and MN, (ii) that the UE is voice-capable, and (ii) that the MN does not support voice-over-packet (VOP) service of the UE, and
• (b) responsive to at least the detecting, causing the UE to not be served, concurrently with the UE being served by the MN over the master connection, by a secondary node (SN) that would engage in user-plane signaling with the UE over a secondary connection between the UE and the SN and that would engage in control-plane signaling with the UE over the master connection,
• wherein causing the UE to not be served, concurrently with the UE being served by the MN over the master connection, by the SN comprises causing the UE to operate with single connectivity with the MN rather than with dual connectivity with the MN and the SN and comprises (i) forgoing setup of the secondary connection for the UE or (ii) tearing down the secondary connection if the secondary connection is already set up.