Patent ID: 9220042
Filing Date: 2015-12-22
Classification: H04W

Abstract:
1. A transmission node in a wireless communication network, comprising: a buffer having a plurality of entries with corresponding addresses for storing data to be transmitted to another node in the network, wherein the data includes a Service Data Unit (SDU) and a Protocol Data Unit (PDU); a transmitting section connected to the buffer for transmitting the data to the other node in the network; a data processing section connected to the buffer for transforming the data between a SDU and a PDU; a re-transmit queue for storing addresses of a plurality of SDUs stored in the buffer and associated sequence numbers assigned to the SDUs, wherein the SDUs require re-transmission; and a control section connected to the buffer, the re-transmit queue and the transmitting section for adding the address of the SDU and the associated sequence number assigned to the SDU to the re-transmit queue, and maintaining the PDU transformed from the SDU in the entry of the buffer after the PDU is transmitted to a mobile node, wherein after a handover of the mobile node from the transmission node to the other transmission node occurs, the data processing section reverse transforms the PDU of which the address are stored in the retransmit queue back to the SDU with the associated sequence number stored in the retransmit queue, and the transmitting section transmits the reverse transformed SDU to the second transmission node, and wherein the control section removes the address of the SDU and the associated sequence number assigned to the SDU from the retransmit queue, and releases the entry with the address when the PDU transmitted from the transmission node to the mobile node is acknowledged within a predefined period, or the predefined period has expired without receiving an acknowledgement of the PDU.