CMT-NC: Improving the Concurrent Multipath Transfer Performance Using Network Coding in Wireless Networks

The growing popularity of multihoming mobile terminals has encouraged the use of concurrent multipath transfer (CMT) to provide network diversity and accelerated content distribution in ubiquitous and heterogeneous wireless network environments. However, CMT severely degrades its performance, which is mostly due to both data reordering required as a result of great path dissimilarity and frequent packet loss due to wireless channel unreliability. Most delivery approaches follow the packet sequence numbers and thereby result in strict in-order and packet-specific reception. Passively adapting to the network variations, those approaches are not general enough to address CMT problems. This paper proposes to apply network coding (NC) principles to CMT, to break the strong binding between data packets and their sequence numbers, and then improve its performance. The proposed CMT-NC solution avoids data reordering to mitigate buffer blocking and compensates for the lost packets to reduce the number of retransmissions. Its specific encoding approach reduces the encoding complexity and fully ensures decoding feasibility. Furthermore, the group-based transmission management enhances the robustness and reliability of the data transfer. Simulation results show how CMT-NC is a highly efficient data transport solution outperforming existing state-of-the-art solutions.