The Impact of TCP Packet Size and Number of TCP Connections in Underwater Wireless Sensor Networks

Transmission in Underwater Wireless Sensor Networks (UWSNs) is a key enabler technology for future oceanmonitoring systems. Owing to the harsh nature of the marine environment, UWSNs possess as a whole set of challenges that are inexistent in traditional Wireless Sensor Networks (WSNs). The only viable transmission medium in UWSNs is acoustic waves which unfortunately suffers from high propagation delay, as well as limited available bandwidth due to the high noise level. There have been numerous research studies on designing different routing and medium access mechanism in WSNs. However, studying systemically the behavior of TCP protocol under different parameters and for different routing protocols in underwater environment has not received much research attention. In this paper, we try to bridge the gap by evaluating the performances of the TCP Vegas as a transport layer for UWSNs with the aim of improving TCP performance in underwater environment. We then, evaluate the effects of varying TCP Packet Size and the density number of TCP connections in the networks under two popular routing protocols namely AODV and DSDV. In addition, we provide some guidelines that will serve for performance tuning. We conclude that, the performances of TCP Vegas using DSDV routing provide a more efficient result than those by using AODV routing in UWSNs.