On Unicast based Recovery for Multicast Content Distribution considering XOR-FEC

In this paper, we propose a fail-safe and efficient download completion scheme for reliable multicast to which FEC (forward error correction) is applied with practical constraints on multicast transmission time. Recently, erasure codes based on XOR operation have become major FEC candidates for multicast content file distribution over the Internet or mobile networks in terms of their recovery performance and processing overheads. In particular LT (Luby transform) codes are effective in a heterogeneous multicast environment because they can achieve higher reliability by expanding the receiving time at each client. However, multicast transmission time can be restricted due to operational reasons considering multicast resource efficiency. In order to assure all the clients of download completion under such conditions, we newly designed a unicast based recovery mechanism considering LT codes characteristics. We confirmed the efficiency of our proposed mechanism by computer simulation