Next Generation Node-B (GNB) and Methods for Mobility Management with Separate User Plane and Control Plane in New Radio (NR) Systems

A base station, comprising:

• a memory;
• and
• a processor in communication with the memory, wherein the processor is configured to:
• operate the base station as a source base station configured with logical nodes including a first central unit (CU) and a first distributed unit (DU), wherein the first CU include a first control plane (CU-CP) for control plane functionality and a first user plane (CU-UP) for user plane functionality;
• encode an XnAP handover request message for transfer by the first CU-CP to a second CU-CP, wherein the second CU-CP is included in a target base station, wherein the target base station is configured with logical nodes including a second DU and a second CU, wherein the second CU includes the second CU-CP and a second CU-UP;
• initiate, before a user equipment (UE) executes a handover, data forwarding from the first CU-UP to the second CU-UP of downlink data packets intended for the UE;
• and
• decode, at the first CU-UP, a first end marker packet that indicates that the first CU-UP is to terminate the data forwarding, wherein the first end marker packet is received from a user plane function (UPF) entity that exchanges data with the base station;
• and
• encode, for transfer from the first CU-UP to the second CU-UP, a second end marker packet that indicates termination of the data forwarding.

An apparatus, comprising

• a memory;
• and
• a processor in communication with the memory, wherein the processor is configured to:
• operate a base station as a source base station configured with logical nodes including a first central unit (CU) and a first distributed unit (DU), wherein the first CU includes a first control plane (CU-CP) for control plane functionality and a first user plane (CU-UP) for user plane functionality;
• encode an XnAP handover request message for transfer by the first CU-CP to a second CU-CP, wherein the second CU-CP is included in a target base station, wherein the target base station is configured with logical nodes including a second DU and a second CU, wherein the second CU includes the second CU-CP and a second CU-UP;
• initiate, before a user equipment (UE) executes a handover, data forwarding from the first CU-UP to the second CU-UP of downlink data packets intended for the UE;
• decode, at the first CU-UP, a first end marker packet that indicates that the first CU-UP is to terminate the data forwarding, wherein the first end marker packet is received from a user plane function (UPF) entity that exchanges data with the source base station;
• and
• encode, for transfer from the first CU-UP to the second CU-UP, a second end marker packet that indicates termination of the data forwarding.

A non-transitory computer-readable storage medium that stores instructions executable by processing circuitry of a base station to:

• operate the base station as a source base station configured with logical nodes including a first central unit (CU) and a first distributed unit (DU), wherein the first CU include a first control plane (CU-CP) for control plane functionality and a first user plane (CU-UP) for user plane functionality;
• encode an XnAP handover request message for transfer by the first CU-CP to a second CU-CP, wherein the second CU-CP is included in a target base station, wherein the target base station is configured with logical nodes including a second DU and a second CU, wherein the second CU includes the second CU-CP and a second CU-UP;
• initiate, before a user equipment (UE) executes a handover, data forwarding from the first CU-UP to the second CU-UP of downlink data packets intended for the UE;
• and
• decode, at the first CU-UP, a first end marker packet that indicates that the first CU-UP is to terminate the data forwarding, wherein the first end marker packet is received from a user plane function (UPF) entity that exchanges data with the base station;
• and
• encode, for transfer from the first CU-UP to the second CU-UP, a second end marker packet that indicates termination of the data forwarding.