A method for a dual packet data convergence protocol entity, comprising: receiving , at a second packet data convergence protocol, PDCP, entity dedicated to carry network coded packet data convergence protocol protocol data units, a plurality of original packet data convergence protocol, PDCP, protocol data units, PDUs, from a first PDCP entity for a radio bearer; coding , at the second packet data convergence protocol, PDCP, entity, the original packet data convergence protocol, PDCP, protocol data units, PDUs, to produce one or more network coded packet data convergence protocol, PDCP, protocol data units, PDUs; and linking original packet data convergence protocol, PDCP, protocol data units, PDUs, to network coded packet data convergence protocol, PDCP, protocol data units, PDUs, by a formula configured to derive the sequence number, SN, of the original packet data convergence protocol, PDCP, protocol data units, PDUs, from the sequence number, SN, of the network coded packet data convergence protocol, PDCP, protocol data unit, PDU, such that the sequence number, SN, for the network coded packet data convergence protocol, PDCP, protocol data units, PDUs, is given by the following linking formula: SN PDCP1 = SN PDCP2 * n - const , SN PDCP1 = SN PDCP2 * n - const , ..., SN(n) PDCP1 = SN PDCP2 * n - const(n), where the multiplying n is the number of original packet data convergence protocol, PDCP, protocol data units, PDUs, used to create a network coded packet data convergence protocol, PDCP, protocol data unit PDU, SN PDCP2 is the sequence number of a network coded PDCP PDU and SN(n) PDCP1 is for the original n PDCP PDU coded into the network coded PDCP PDU, and const(n) represents a constant for the n original PDCP PDU coded into the network coded PDCP PDU. receiving , at a second packet data convergence protocol, PDCP, entity dedicated to carry network coded packet data convergence protocol protocol data units, a plurality of original packet data convergence protocol, PDCP, protocol data units, PDUs, from a first PDCP entity for a radio bearer; coding , at the second packet data convergence protocol, PDCP, entity, the original packet data convergence protocol, PDCP, protocol data units, PDUs, to produce one or more network coded packet data convergence protocol, PDCP, protocol data units, PDUs; and linking original packet data convergence protocol, PDCP, protocol data units, PDUs, to network coded packet data convergence protocol, PDCP, protocol data units, PDUs, by a formula configured to derive the sequence number, SN, of the original packet data convergence protocol, PDCP, protocol data units, PDUs, from the sequence number, SN, of the network coded packet data convergence protocol, PDCP, protocol data unit, PDU, such that the sequence number, SN, for the network coded packet data convergence protocol, PDCP, protocol data units, PDUs, is given by the following linking formula: SN PDCP1 = SN PDCP2 * n - const , SN PDCP1 = SN PDCP2 * n - const , ..., SN(n) PDCP1 = SN PDCP2 * n - const(n), where the multiplying n is the number of original packet data convergence protocol, PDCP, protocol data units, PDUs, used to create a network coded packet data convergence protocol, PDCP, protocol data unit PDU, SN PDCP2 is the sequence number of a network coded PDCP PDU and SN(n) PDCP1 is for the original n PDCP PDU coded into the network coded PDCP PDU, and const(n) represents a constant for the n original PDCP PDU coded into the network coded PDCP PDU. <EOS>