On the use of sliding LT code in underwater acoustic real-time data transfer with high propagation latency

The data-link layer protocol is of great significance for the effectiveness and reliability of the transmission. In terrestrial wireless networks, there are three error control protocols in data-link layer, stop-wait ARQ, go-back-N ARQ and selective ARQ. Moreover, LT code, an advanced error control mechanism, is proposed and widely used in deep space communications or other erasure channels. However, since underwater sound speed is comparatively slow, the protocol design needs to take the characteristics of the underwater acoustic channel into consideration in order to make efficient use of the channel. In this paper, a novel data transfer protocol based on sliding LT code (SLTC) is proposed to solve the underwater acoustic data transfer problem. We define the main performance metric in terms of the transmission efficiency to evaluate and compare three different protocols, stop-wait ARQ, M-ARQ and the data transfer protocol based on SLTC. Simulation results show that the impact of the transmission distance on the transmission efficiency of the data transfer protocol based on SLTC is less than that of the other two protocols.