Underwater wireless sensor networks (UWSNs) facilitate a wide range of aquatic applications in various domains. However, the harsh underwater environment poses challenges like low bandwidth, long propagation delay, high bit error rate, high deployment cost, irregular topological structure, etc. Node mobility and the uneven distribution of sensor nodes create void holes in UWSNs. Void hole creat...

Regular activity of the human is being extended to marine and sub-marine regions. Invention of war activity and marine research on minerals and bio-diversity is leading to install wireless sensor devices in deep underwater system. The underwater sensors and network areas are applied through a number of applications like research, water games, self-defense against enmity, finding of minerals and...

(U) In the context of an information-based society the ability to reliably retrieve, transfer and process large quantities of data in a timely fashion becomes a critical technology issue. In the context of integrating submarine offboard sensors and physically supporting data connectivity with terrestrial networks: reliable, high bandwidth communications ranks as an extremely difficult technical...

The large-scale mobile Underwater Wireless Sensor Network (UWSN) is a useful networking paradigm to explore underwater environments. The characteristics of mobile UWSNs, such as low communication bandwidth, large propagation delay, and floating node mobility are significantly different from wireless sensor networks. In this paper, we propose a new efficient routing protocol, called multi-path r...

This paper describes online simultaneous underwater image gathering, utilizing stationary camera node and movable camera node. We consider applying them to investigate the conditions of marine ecosystem around coral leaf at Okinawa, Japan. The framework of our proposed underwater image gathering system and current development of the camera node prototypes are described. By utilizing two types o...

We consider a “Social Group” of networked nodes, seeking a “universe” of segments. Each node has subset of the universe, and access to an expensive resource for downloading data. Alternatively, nodes can also acquire the universe by exchanging segments among themselves, at low cost, using a local network interface. While local exchanges ensure minimum cost, “free riders” in the group can exploi...

In this study, we introduce a new media access control (MAC) protocol that adaptively changes time division multiple access (TDMA) frame size and slot duration in order to upgrade performance of underwater sensor networks. Throughput of underwater sensor networks is very low compared to a radio frequency (RF) network; the reason is a very long propagation delay and a very low bit rate. To solve...

<p>Underwater sensor networks (UWSNs) are recently recognized as a promising method for monitoring and exploring the underwater environment. Due to real-time remote data requirements, UWSN has become preferred network large extent. But reliable efficient secure transmission receiver is one of most important challenges UWSNs, often suffer from irreplaceable batteries high latency long-dist...

Most of the existing node depth-adjustment deployment algorithms for underwater wireless sensor networks (UWSNs) just consider how to optimize network coverage and connectivity rate. However, these literatures don't discuss full network connectivity, while optimization of network energy efficiency and network reliability are vital topics for UWSN deployment. Therefore, in this study, a depth-ad...

There are many technical challenges for designing large-scale underwater sensor networks, especially the sensor node localization. Although many papers studied for large-scale sensor node localization, previous studies mainly study the location algorithm without the cross layer design for localization. In this paper, by utilizing the network hierarchical structure of underwater sensor networks,...