MOBICOM

As multi-channel communication is becoming more and more common in Radio Frequency (RF) arena, acoustic communication protocols have also started to adopt the same concept to utilize multiple channels in Underwater Sensor Networks (UWSN). Although the ...

Underwater environmental parameters vary with time and can negatively impact the quality of communication. The adaptive control system suggested attempts to improve communication in underwater networks where environmental conditions are stochastic and ...

Through the use of network simulators we are able to test and examine different combinations of protocols in low cost and controlled environments. To ensure the accuracy of these simulators it is crucial that they consistently expand and enhance their ...

The recent uptake of non-acoustic underwater transmission systems suggests that in the near future it will be common for underwater devices to incorporate different physical communication technologies. Such devices are typically described as multimodal. ...

This paper considers the use of Combined Free/Demand Assignment Multiple Access (CFDAMA) for Underwater Acoustic Networks (UANs). The long propagation delay places severe constraints on the trade-off between end-to-end delay and the achievable channel ...

Low-data rate, non-coherent algorithms were tested at 10 km distances to measure reliability and robustness when combined with convolutional turbo encoding techniques. The system was constrained to hardware specifications limiting bandwidth at low ...

We address the problem of object tracking in an underwater acoustic sensor network in which distributed nodes measure the strength of field generated by moving objects, encode the measurements into digital data packets, and transmit the packets to a ...

Oceanographic monitoring in the Arctic is important for understanding the physical, chemical, and biological environments, particularly given the enhanced warming of high latitude regions compared with the global average. Ongoing in situ monitoring in ...

Underwater acoustic communications experiments often involve custom implementations of schemes and protocols for the physical and data link layers. However, most commercial modems focus on providing reliable or optimized communication links, rather than ...

This paper introduces the idea of ECO-friendly underwater acoustic communications via utilizing prediction techniques. The ultimate goal of the research is to avoid the interference caused by man-made noise to marine mammals. Specifically, we first ...

The ability to detect abnormal conditions is of great importance for the survivability of marine robots. However, false alarms can occur and may lead to unnecessary interruption of robotic missions. This paper presents recent results on anomaly ...

This paper concerns the implementation and testing of a protocol that two honest parties can efficiently use to share a common secret session key. The protocol, based on the Fully Hashed Menezes-Qu-Vanstone (FHMQV) key agreement, is optimized to be used ...

Due to the atypical characteristics of the physical media in underwater acoustic sensor networks (UW-ASN)--mostly because of long propagation delay, low bandwidth and high error rate--several challenges arise while designing the MAC protocol. In this ...

In many practical underwater sensor networks covering a large area, only a small portion of the data may be collected in a certain time interval due to limited capacity of acoustic communications underwater. This posed a great challenge for situation ...

Recent technological advances have brought to the end-user market smartphones that are able to remain fully-functional even when submerged under water. This capability will soon enable the commercialization of a plethora of exciting smartphone apps, ...

Many papers discuss challenges and solutions pertaining to underwater networks that make use of acoustic waves for either detection or communication purposes. However, no known solution yet exists for jointly conceiving network performing both tasks. ...

A low-frequency doubly-spread acoustic channel is used to illustrate the effectiveness of iterative (turbo-) equalization for rapidly changing communications channels. The channel is modeled as a 1 km shallow ocean channel and its physical parameters ...

Short range wireless high data rate underwater communication systems become increasingly important. We provide the implementation, the setup and measurement results of the bit rate of our optical wireless underwater communication system in the Baltic ...

Magnetic induction (MI) has shown a great potential for underwater communications due to its immunity to acoustic noise and low latency. However, the transmission distance of MI is limited since the magnetic field attenuates very fast in the near field. ...

This paper presents a new entropy minimization criterion and corresponding algorithms that are used for both symbol timing and carrier frequency recovery for underwater acoustic receivers. It relies on the entropy estimation of the eye diagram and the ...

Multi-modal communication methods have been proposed for underwater wireless networks (UWNs) to tackle the challenging physical characteristics of underwater wireless channels. These include the use of acoustic and optic technology for range-dependent ...

Source localization is a basic problem in underwater acoustics. Many solving approaches have been developed, and the matched-field processing (MFP) is one of the mostly-studied. However, MFP is sensitive to the mismatch problem and performs well only ...

Autonomous underwater vehicles (AUVs) are the platform of choice for ocean exploration and surveillance in the ice-covered regions. Due to the large attenuation of radio signals in water, acoustic communications have been the major technique for ...

Underwater acoustic channel is complex and modeling it is a challenging task. In this paper we present a geometry based approach to characterize the path gains encountered in a shallow underwater acoustic communications channel. The system geometry is ...

Matched field processing (MFP) is a classic approach to locate underwater acoustic source where source level is relatively high without environment mismatch. However, when we wish to track a source radiating weak signal, the performance of MFP degrades ...

To evaluate the performance of a communication link, signals are often modeled using software and validated against actual data measurements for a more reliable analysis. In this work a measurement campaign is run to analyze the effect of noise on a ...