Next generation node-b (gnb) and methods for mobility management with separate user plane and control plane in new radio (nr) systems

A non-transitory computer-readable storage medium that stores instructions for execution by processing circuitry of a Next Generation Node-B (gNB), the gNB configurable to operate as a source gNB (S-gNB), the S-gNB configured with logical nodes including a gNB central unit (gNB-CU) and a gNB distributed unit (gNB-DU), the gNB-CU comprising a control plane (CU-CP) for control-plane functionality, and a user plane (CU-UP) for user-plane functionality, the operations to configure the processing circuitry to:

• encode, for transfer from the CU-CP of the S-gNB to a CU-CP of a target gNB (T-gNB), an XnAP handover request message that indicates an Xn handover of a User Equipment (UE) from the S-gNB to the T-gNB;
• decode, at the CU-CP of the S-gNB, an XnAP handover request acknowledgement message that acknowledges the Xn handover of the UE from the S-gNB to the T-gNB, the XnAP handover request acknowledgement message received from the CU-CP of the T-gNB;
• in response to reception of the XnAP handover request acknowledgement message:
• decode, at the CU-UP of the S-gNB, one or more end marker packets that indicate that the S-gNB is to refrain from forwarding, from the CU-UP of the S-gNB to a CU-UP of the T-gNB, downlink data packets intended for the UE, wherein the one or more end marker packets are received from a user plane function (UPF) entity that exchanges data with the S-gNB and the T-gNB.

A non-transitory computer-readable storage medium that stores instructions for execution by processing circuitry of a Next Generation Node-B (gNB), the gNB configurable to operate as a target gNB, the T-gNB configured with logical nodes including a gNB central unit (gNB-CU) and a gNB distributed unit (gNB-DU), the gNB-CU comprising a control plane (CU-CP) for control-plane functionality, and a user plane (CU-UP) for user-plane functionality, the operations to configure the processing circuitry to:

• decode, at the CU-CP of the T-gNB, an XnAP handover request message that indicates an Xn handover of a User Equipment (UE) from a source gNB (S-gNB) to the T-gNB, the XnAP handover request message received from a CU-CP of the S-gNB;
• decode, at the CU-UP of the T-gNB, downlink data packets intended for the UE, the downlink data packets forwarded from the CU-UP of the S-gNB;
• and
• monitor, at the CU-UP of the T-gNB, for one or more end marker packets from the CU-UP of the S-gNB that indicate that the CU-UP of the S-gNB is to refrain from forwarding, to the CU-UP of the T-gNB, of the downlink data packets intended for the UE.