A cost-efficient hybrid redundancy coding scheme for wireless storage systems

With distributed storage technique becoming a promising technology for storing massive data in wireless environment, how to improve the reliability of the storage systems has become the focus of researchers. As a redundancy scheme, the erasure coding has been widely used because of its high fault tolerance and low storage overhead performance. However, a large amount of repair overhead consumed to reconstruct lost data has become the most significant issue in erasure-coded storage systems. In this paper, a wireless heteroge-neous storage network with two-layer is designed, where processing units and storage nodes communicate cooperatively. Furthermore, with the consideration of the access frequency skew of stored information and the performance difference of storage nodes, we propose a novel repairable fountain code scheme based on partial duplication technique (PD-RFC), which can modify the repair bandwidth and improve the availability of links between nodes without almost increasing additional storage space overhead. Furthermore, a hybrid code scheme combined by PD-RFC scheme and RFC scheme is designed for the heterogeneous two-layer storage network. The simulation results have shown that the hybrid scheme significantly outperforms other redundant schemes in energy communication cost saving.