An Efficient Hierarchical Error Recovery Method for Hybrid Broadcast/Communication Networks

摘要

This paper proposes a hierarchical error recovery method for the hybrid mobile broadcast/communication networks. The mobile broadcast network (e.g., DVB-T/H, T-DMB) transmits the base forward error correction (FEC) and the multimedia content at the same time for the error recovery. However, the occurrence of errors is different due to the receiving environment of the individual mobile broadcast network, and not all the base FECs can recover errors. The server retransmits the enhanced-FEC (E-FEC) to a terminal through the individual mobile communication network and a terminal can try to recover the packet with errors which the base FEC cannot recover. If there are more retransmitted source data to a user, the overhead of a user and the communication network will increase because the individual mobile communication is a subscription-based network. Therefore, this paper proposes a hierarchical error recovery method, and the E-FEC with higher channel coding rate than base FEC is generated and transmitted. The proposed method in this paper transmits only the redundancy data for the error recovery when errors occur, and reduces the resource by 50%-80% compared with the retransmission of the source. If the source bit rate is 800 kbps, for instance, the packet error ratio is 10%, and if a user watches a broadcast content for one hour, the amount of retransmitted data is 80 kbps x 3600 = 36 MBytes, but that of the proposed method in this paper is 7.2-18 MBytes.