Multi-connectivity using time division multiplexing

An apparatus, comprising:

• a processor, wherein to configure a user equipment device (UE) for time-division multiplexing (TDM)-based multi-connectivity handover with a source base station (SBS) and a target base station (TBS), the processor is configured to cause the UE to:
• encode a measurement report for transmission to the SBS, the measurement report triggered based on a measurement event configured by the SBS;
• decode radio resource control (RRC) signaling from the SBS, the RRC signaling including a handover command in response to the measurement report
• encode uplink (UL) data for transmission to the SBS, wherein transmission of the UL data to the SBS is time-division multiplexed with communications between the UE and the TBS during the handover;
• perform a random access channel (RACH) procedure with the TBS during the handover, while maintaining connectivity with the SBS;
• and
• release the SBS only after the RACH procedure with the TBS is successfully completed.

A source base station (SBS), comprising:

• a radio;
• and
• a processor operably connected to the radio and configured to cause the SBS to:
• decode a measurement report from the UE, the measurement report triggered based on a measurement event configured by the SBS;
• encode radio resource control (RRC) signaling for transmission to the UE, the RRC signaling including a handover command in response to the measurement report and a handover acknowledgment from a target base station (TBS), wherein the handover command is associated with a time-division multiplexing (TDM)-based multi-connectivity handover;
• decode uplink (UL) data received from the UE, wherein transmission of the UL data is time-division multiplexed with communications between the UE and the TBS during the handover;
• and
• after successful completion of a random access channel (RACH) procedure between the UE and the TBS during the handover, release the UE.

A user equipment device (UE) comprising:

• a radio;
• and
• a processor operably connected to the radio and configured to cause the UE to:
• encode a measurement report for transmission to a source base station (SBS), the measurement report triggered based on a measurement event configured by the SBS;
• decode radio resource control (RRC) signaling from the SBS, the RRC signaling including a handover command in response to the measurement report, wherein the handover command is associated with a time-division multiplexing (TDM)-based multi-connectivity handover;
• encode uplink (UL) data for transmission to the SBS, wherein transmission of the UL data to the SBS is time-division multiplexed with communications between the UE and a target base station (TBS) during the TDM-based multi-connectivity handover;
• perform a random access channel (RACH) procedure with the TBS during the TDM-based multi-connectivity handover, while maintaining connectivity with the SBS;
• and
• release the SBS only after the RACH procedure with the TBS is successfully completed.