Network Coding Based Cooperative Repair for Cache-enabled Wireless Network

In wireless coded cache network, data contents are cached in a number of mobile devices using an erasure correcting code, and thus users can retrieve data contents from other mobile devices using device-to-device communication. In this paper, we consider the repair problem when multiple devices that cache data contents fail or leave the network. By exploiting the wireless broadcast nature, we formulate the repair problem over the broadcast channels using an integer linear programming formulation, aiming at minimizing the number of necessary broadcast transmissions. We also study the construction of repair codes and propose a decentralized repair coding method. Simulation results show that the performance using our method outperforms that of traditional cooperative repair scheme, which is the basic repair method for wired distributed storage systems.