A network coding based protocol for reliable data transfer in underwater acoustic sensor

VBF-NC (Vector Based Forwarding-Network Coding) is a reliable transport protocol for UWASNs (Underwater Acoustic Sensor Networks). It transfers packets, coded by network coding, over relay node sets, which are established by VBF (Vector Based Forwarding) routing protocol. However, only the error correction function of network coding is used by VBF-NC, the most important inbeing of network coding, which cannot only improve the throughput of network but also reduce transmission overhead, is not used by VBF-NC. So, in this paper, a network coding based protocol, called Multiple Paths and Network Coding (MPNC), is proposed. In MPNC, three disjoint paths are established firstly, and then, two groups of packets A and B, coded by network coding, are transmitted over the two side paths individually, and another group of packets C (C = A ⊕ B) are transmitted over the middle path. The results of mathematical analysis and simulations show that, compared with VBF-NC, MPNC not only improve the throughput of network but also has a higher data delivery ratio and lower energy consumption without reducing the data transmission reliability.