Packet data convergence protocol data recovery

A method, in a base station comprising a central unit and one or more distributed units (DU), for synchronizing radio link control re-establishment between a user equipment (UE) and a DU, the method comprising:

• obtaining an indication that an uplink and/or downlink outage has occurred between the DU and the UE;
• requesting a user plane (UP) data processing apparatus of the CU to retransmit, via the DU, any data protocol units previously transmitted to the UE which were unacknowledged by the UE;
• and,
• responsive to the request, retransmitting, by the UP data processing apparatus and via the DU, any data protocol units previously transmitted to the UE which were unacknowledged by the UE.

A base station comprising a control plane (CP) data processing apparatus and a user plane (UP) data processing apparatus, the CP data apparatus and the UP data processing apparatus comprising processing circuity configured to:

• obtain, in the CP data processing apparatus, an indication that an uplink and/or downlink outage has occurred between a distributed unit (DU) of the base station and a user equipment (UE);
• send a request from the CP data processing apparatus to the UP data processing apparatus, to instruct the UP data processing apparatus to retransmit, via the DU, any data protocol units previously transmitted to the UE which were unacknowledged by the UE;
• and,
• responsive to the request, retransmitting, by the UP data processing apparatus and via the DU, any data protocol units previously transmitted to the UE which were unacknowledged by the UE.