A device for wireless communications includes one or more protocol processors for executing a protocol stack, the one or more protocol processors configured to generate a first RLC (Radio Link Control) PDU (Protocol Data Unit) with data from a first upper-layer PDU and transmit the first RLC PDU to a counterpart base station RLC, generate a second RLC PDU, with its poll bit set, with data from a second upper-layer PDU and transmit the second RLC PDU to the counterpart base station RLC, and receive a status PDU from the counterpart base station RLC that indicates a status of the first and second RLC PDUs.