Rollout Algorithms for Data Storage- and Energy-Aware Data Retrieval Using Autonomous Underwater Vehicles

Butt

et al. 2018

Sensors

Sensor nodes in underwater sensor networks may acquire data at a higher rate than their ability to communicate over underwater acoustic channels. Autonomous underwater vehicles may mitigate this mismatch by offloading high volumes of data from the sensor nodes and ferrying them to the sink. Such a mode of data transfer results in high latency. Occasionally, these networks need to report high priority events such as catastrophes or intrusions. In such a scenario the expectation is to have a minimal end-to-end delay for event reporting. Considering this, underwater vehicles should schedule their visits to the sensor nodes in a manner that aids efficient reporting of high-priority events. We propose the use of the Value of Information metric in order to improve the reporting of events in an underwater sensor network. The proposed approach classifies the recorded data in terms of its value and priority. The classified data is transmitted using a combination of acoustic and optical channels. We perform experiments with a binary event model, i.e., we classify the events into high-priority and low-priority events. We explore a couple of different path planning strategies for the autonomous underwater vehicle. Our results show that scheduling visits to sensor nodes, based on algorithms that address the value of information, improves the timely reporting of high priority data and enables the accumulation of larger value of information.

Section: Related Workmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Value of Information Based Data Retrieval in UWSNs

Butt

et al. 2018

Sensors

IEEE Trans. Wireless Commun.

“…In [29], the sink-to-node downlink is based on AC, and the uplink is serviced through OC. A similar concept is suggested in [30], [31] where AC is used to request AUVs to approach and collect data through OC. On the contrary, in [32], OC is employed for positioning of a swarm of AUVs, and AC is used for data exchange between the AUVs.…”

Section: Overview Of Multimodal Systemsmentioning

confidence: 99%

On the Relationship Between the Underwater Acoustic and Optical Channels

Diamant

Campagnaro

Grazia

et al. 2017

Self Cite

Wireless transmissions in water are mostly carried out via long-range (but low-rate) underwater acoustic communications, or short-range (but high-rate) underwater optical communications. In this paper we are interested in finding whether a statistical relationship exists between underwater acoustics and optics. Besides the theoretical interest of such relationship, predicting the quality of the optical link through acoustics is also relevant in the context of a multimodal system with both acoustics and optics. Our study is based on a large dataset acquired during the NATO ALOMEX'2015 expedition. During this experiment, we simultaneously measured several characteristics of the acoustic and optical links at multiple locations, reflecting a diversity of sea environments. Our results, show a strong correlation between the properties of the acoustic link and the reliability of optical communications. This correlation makes it possible to predict the state of the underwater optical link at a certain depth and range. Due to the complexity of the acoustic and optical channels, we could not find the source of this correlation. This work is therefore aimed to stimulate a theoretical study of the mutual properties of underwater acoustic and optical communication links. For reproducibility, we share the processed data from the experiment.

“…In [15] the authors present a multi-level Q-learning-based routing protocol for hybrid acoustic/optical communication. The work in [16] investigates optimal trajectory planning decisions for multiple AUVs in the presence of constraints on energy, data storage and retrieval requirements. Optical communications are exploited to retrieve data from sensors.…”

Section: Introduction and Related Workmentioning

confidence: 99%

“…The switch strategy is configurable by the user. We employ our simulator to test a scenario akin to [16], where an AUV moves to retrieve data from a number of bottom nodes. Our results prove that our optical/acoustic switch strategy (based on the perceived power over either link) is effective, and demonstrate the effect of different environmental parameters on the quality of the communication processes.…”

Section: Introduction and Related Workmentioning

confidence: 99%

Simulation of multimodal optical and acoustic communications in underwater networks

Campagnaro

Favaro

Guerra

et al. 2015

OCEANS 2015 - Genova

Self Cite

In this paper, we consider data muling over a network of fixed sensors by employing a mobile Autonomous Underwater Vehicle (AUV). We approach the problem using both acoustic and optical communications together in a multi-modal hybrid network: the most appropriate physical layer is chosen according to the quality of the transmissions that take place over time. We consider three distinct cases of water type: clear, coastal and turbid water, in order to test the system behavior under different conditions. The ambient light noise is realistically reproduced via the Hydrolight software and taken into account, due to its important contribution to the optical SNR in shallow waters. Finally, we simulate the performance of the system using the DESERT Underwater framework during missions of interest in different channel conditions and network depth. Our results show the effectiveness of a multi-modal underwater network in the cases of clear and coastal waters