Re-transmission of PDCP PDUS by centralized nodes of a RAN architecture

An apparatus including a Centralized Unit of a Next Generation NodeB (gNB-CU) comprising:

• one or more processors to:
• communicate with a plurality of Distributed Units of the Next Generation NodeB (gNB-DUs);
• buffer packet data convergence protocol (PDCP) Protocol Data Units (PDUs) already transmitted to a first gNB-DU of the plurality of gNB-DUs until the PDCP PDUs have been acknowledged to be successfully delivered to a user equipment (UE);
• detect mobility of the UE receiving the PDCP PDUs from the first gNB-DU of the plurality of gNB-DUs to a second gNB-DU of the plurality of gNB-DUs;
• detect that particular PDCP PDUs transmitted to the first gNB-DU from which the mobility of the UE is detected, were undelivered by the first gNB-DU, to the UE;
• and
• retransmit, in response to the detection that the particular PDCP PDUs were undelivered, the particular PDCP PDUs to the second gNB-DU to which the mobility of the UE is detected.

A system to implement a portion of a Radio Access Network (RAN), comprising:

• a plurality of Distributed Units of a Next Generation NodeB (gNB-DU);
• and
• a Centralized Unit of the Next Generation NodeB (gNB-CU), the gNB-CU being connected to the plurality of gNB-DUs, the gNB-CU operating to:
• buffer packet data convergence protocol (PDCP) Protocol Data Units (PDUs) already transmitted to a first gNB-DU of the plurality of gNB-DUs until the PDCP PDUs have been acknowledged to be successfully delivered to a user equipment (UE);
• receive an indication, from the first gNB-DU of the plurality of gNB-DUs, of a radio link outage between the first gNB-DU and the UE;
• detect that particular PDCP PDUs transmitted to the first gNB-DU from which the indication is received, were undelivered by the first gNB-DU to the UE;
• and
• retransmit, in response to the detection that the particular PDCP PDUs were undelivered, the particular PDCP PDUs to a second gNB-DU, of the plurality of gNB-DUs, to which the UE is attached.