In this paper, an important property of acoustic signal that the speed of acoustic signal varies with water depth has been considered to explore a new routing protocol in UASNs. It implies that the shortest end-to-end delay path may not be the shortest path directly from the source to the sink. Based on this property, a per-hop based routing protocol, named sound speed adaptive routing protocol (SSARP), is proposed. SSARP takes the acoustic speed in different water depth into consideration. SSARP can find a path with a short end-to-end delay to transmit the data. The simulation results also verify that SSARP actually reduces the end-to-end delay and outperforms other routing protocols in terms of end-to-end delay.
International Journal of Ad Hoc and Ubiquitous Computing 16(3), pp.149-160