Patent ID: 8228869
Filing Date: 2012-07-24
Classification: H04L,H04W

Abstract:
1. A communication method performed in a source node of a telecommunication system, the method comprising: receiving Service Data Units, SDUs, for transmission to a mobile communication device; storing a copy of the SDUs in an SDU management buffer; passing the SDUs to a concatenation and segmentation unit to generate Protocol Data Units, PDUs; storing the PDUs in a transmit buffer for transmission to the mobile communication device; sending a feedback message to the SDU management buffer identifying an SDU that can be removed from the SDU management buffer when, for Unacknowledge Mode, UM, data, the PDUs corresponding to that SDU have been forwarded from the transmit buffer or when, for Acknowledge Mode, AM, data, receipt of the PDUs corresponding to that SDU have been acknowledged by the mobile communication device; in response to the receipt of the feedback message, allowing removal of the identified SDU from the SDU management buffer; and during handover of the mobile communication device from the source node to a target node, forwarding SDUs for the mobile communication device to the target node in dependence upon the SDUs stored in said SOU management buffer.