Interflow Network Coding Approaches for Data Heterogeneous Unicast Sessions in Wireless Networks

The authors investigate the problem of reliable unicast transmissions in wireless ad hoc and WLAN/WiMAX networks. Currently, approaches using network coding show several-fold gain in terms of bandwidth efficiency over the traditional technique, “store and forward”. However, most of these approaches have assumed that all the information flows have the same packet size, while the others consider transmission flows with different size packets, then overcome the size-difference issue by padding more dummy data into the smaller size packets. In their approach, by exploiting the size differences of packets on different flows, the authors introduce a new technique at the relay node/access point/base station to improve network bandwidth efficiency. In particular, a symbol-adjusted technique has been proposed in creating coded packets to improve the reliability of transmissions. Both analytical and simulation results show that the proposed technique significantly improves the network performance over the current technique.