A method performed in a telecommunication system, the method comprising: at a source node: receiving, a sequence of PDCP Service Data Units, SDUs, for transmission to a mobile communication device; appending a sequence number to each PDCP SDU; storing a copy of the PDCP SDUs; the method being characterized by: ciphering the PDCP SDUs; passing the ciphered PDCP SDUs with appended sequence numbers to an Outer ARQ entity for segmentation; segmenting the ciphered PDCP SDUs with appended sequence numbers to generate Outer ARQ segments; generating and appending a respective Outer ARQ header to each Outer ARQ segment to generate a corresponding Outer ARQ Protocol Data Unit, PDU; sending the generated Outer ARQ PDUs to the mobile communication device; and sending a handover request to a target node; at the target node: receiving the handover request from the source node and sending a handover response to the source node in response to the handover request; at the source node: receiving the handover response from the target node; sending a handover command to the mobile communication device; and forwarding stored PDCP SDUs with their appended sequence number to the target node; and at a target node: receiving PDCP SDUs, from the source node and sending from the target node to a mobile communication device, Outer ARQ PDUs corresponding to the PDCP SDUs received from the source node. at a source node: receiving, a sequence of PDCP Service Data Units, SDUs, for transmission to a mobile communication device; appending a sequence number to each PDCP SDU; storing a copy of the PDCP SDUs; the method being characterized by: ciphering the PDCP SDUs; passing the ciphered PDCP SDUs with appended sequence numbers to an Outer ARQ entity for segmentation; segmenting the ciphered PDCP SDUs with appended sequence numbers to generate Outer ARQ segments; generating and appending a respective Outer ARQ header to each Outer ARQ segment to generate a corresponding Outer ARQ Protocol Data Unit, PDU; sending the generated Outer ARQ PDUs to the mobile communication device; and sending a handover request to a target node; receiving, a sequence of PDCP Service Data Units, SDUs, for transmission to a mobile communication device; appending a sequence number to each PDCP SDU; storing a copy of the PDCP SDUs; the method being characterized by: ciphering the PDCP SDUs; passing the ciphered PDCP SDUs with appended sequence numbers to an Outer ARQ entity for segmentation; segmenting the ciphered PDCP SDUs with appended sequence numbers to generate Outer ARQ segments; generating and appending a respective Outer ARQ header to each Outer ARQ segment to generate a corresponding Outer ARQ Protocol Data Unit, PDU; sending the generated Outer ARQ PDUs to the mobile communication device; and sending a handover request to a target node; ciphering the PDCP SDUs; passing the ciphered PDCP SDUs with appended sequence numbers to an Outer ARQ entity for segmentation; segmenting the ciphered PDCP SDUs with appended sequence numbers to generate Outer ARQ segments; generating and appending a respective Outer ARQ header to each Outer ARQ segment to generate a corresponding Outer ARQ Protocol Data Unit, PDU; sending the generated Outer ARQ PDUs to the mobile communication device; and sending a handover request to a target node; at the target node: receiving the handover request from the source node and sending a handover response to the source node in response to the handover request; at the source node: receiving the handover response from the target node; sending a handover command to the mobile communication device; and forwarding stored PDCP SDUs with their appended sequence number to the target node; and receiving the handover response from the target node; sending a handover command to the mobile communication device; and forwarding stored PDCP SDUs with their appended sequence number to the target node; and at a target node: receiving PDCP SDUs, from the source node and sending from the target node to a mobile communication device, Outer ARQ PDUs corresponding to the PDCP SDUs received from the source node.