Patent ID: 7733782

Claim:
A method for avoiding unnecessary retransmissions in a packet-based radio communication system, said method comprising: exchanging transmission state information between upper transmitting and lower transmitting retransmission functional entities respectively located at first and second protocol layers respectively in first and second transmitting network nodes, said first and second nodes being different nodes; said lower transmitting retransmission functional entity receiving retransmitted data packets from said upper transmitting retransmission functional entity; said lower transmitting retransmission functional entity providing a first list comprising sequence numbers of data packets retransmitted by said upper transmitting retransmission functional entity; said lower transmitting retransmission functional entity providing a second list comprising sequence numbers of data packets acknowledged by a corresponding receiving lower receiving retransmission functional entity; and performing inter-layer coordination of retransmissions from said first and second protocol layers based on said exchanged transmission state information, whereby said upper and lower transmitting retransmission functional entities are prevented from retransmitting the same data packets, and said lower transmission retransmission functional entity retransmitting data packets not found in both said first and second lists, wherein said transmission state information relates to a status of reception and/or transmission of the data packets.