OptoCOMM and SUNSET to enable large data offloading in Underwater Wireless Sensor Networks

In this paper we present the initial implementation of an integrated optical and acoustic system that can enable large data transfer between mobile and static nodes in Underwater Wireless Sensor Networks (UWSNs). The proposed system is based on the OptoCOMM optical modem and on the SUNSET Software Defined Communication Stack (S-SDCS) framework. The OptoCOMM modem allows to overcome the limits of maximum data rate and bandwidth imposed by the use of acoustic communication by providing a data rate of 10Mbps. SUNSET SDCS instead has been used to provide networking and fragmentation capabilities to efficiently offload large data in UWSNs. The performance of the proposed approach has been evaluated through in lab experiments where large files with arbitrary sizes have been optically transferred. The results achieved show that our system is able to transfer up to 1.5 GBytes of data in short time

Double-frequency buck converter as a candidate topology for integrated envelope elimination and restoration applications in power supply of RFPAs

This paper proposes the use of double-frequency (DF) buck converter architecture consisting of a merged structure of high and low frequency buck cells as a candidate topology for envelope elimination and restoration (EER) applications and integrated power supply of RF power amplifiers (RFPA) to obtain favorable tradeoffs in terms of efficiency, switching ripple, bandwidth, and tracking capability. It is shown that having two degrees of freedom in designing the DF buck helps to achieve high efficiency, low output ripples, and tracking capability with low ripples, simultaneously. A comparison analysis is done with regards to the mentioned performance indexes with the standard and three-level buck converters; in addition, the results are validated in HSPICE in BSIM3V3 0.35-µm CMOS process.Peer ReviewedPostprint (author's final draft

Natural protected areas network - necessity for conversation of biodiversity

Legal regulation of protected areas in Albania has been focused on the complex legislation fragmenting and non organic , often inefficient. Adoption of the Law Nr. 8906 “On protected areas” created the posibilities to coordinate the institutional framework for planning, management and sustainable development of protected areas which led to a legal and institutional revolution. In fact, the legal framework provides an unbreakable bond between natural values (diversity of animals, plants and forests, biological complexes, biotypes, etc.), as far as and anthropic ones (scenic and panoramic sizes, models and management methods appropriate environmental restoration for achieve integration between the human and natural environment, promoting education and training of scientific and environmental activities, protection of ecological balance and its recovery, etc.). Special attention need to review and especially to implement the environmental laws and decisions in Albani

Biodiversity planning and management in protected areas _ the case of the burnning pine and beech in the National Park " Drenova Fir"

Among the major problems of managing a protected area is also its zoning. This differentiation of the internal zoning of the area in order to protect scientific values, ecological, touristic and helps protect biodiversity. In accordance with these values determines the character of anthropogenic activity level, providing both protection and return its values in a powerful generators of income generation and sustainable development basis. In our country are revealed many protected areas, which accounts for around 13 % of the country surface. But only three parks are preparing management plans along with their zoning. All other protected areas are still without a plan and without Zoning Managment. So, in the same situation is the National Park “Drenova Fir”, which recently underwent the major damage values by brutal anthropogenic interference burning up 70 % of total surface and in a largely disappearance of beech and fir species. In our referral are concentrated precisely in this zoning park, as an integral part of its management plan. Particular attention has been paid based on zoning criteria: biodiversity, unique importance and fragility of the ecosystem values. Field exploring these and other basic criteria after the last summer firing, we proposed two schemes of zoning park . This will help in the design of accurate management plans to protect this area, a necessary condition for maintaining the bidiversit

Finding MARLIN: exploiting multi-modal communications for reliable and low-latency underwater networking

This paper concerns the smart exploitation of multimodal communication capabilities of underwater nodes to enable reliable and swift underwater networking. To contrast adverse and highly varying channel conditions we define a smart framework enabling nodes to acquire knowledge on the quality of the communication to neighboring nodes over time. Following a model-based reinforcement learning approach, our framework allows senders to select the best forwarding relay for its data jointly with the best communication device to reach that relay. We name the resulting forwarding method MARLIN, for MultimodAl Reinforcement Learning-based RoutINg. Applications can choose whether to seek reliable routes to the destination, or whether faster packet delivery is more desirable. We evaluate the performance of MARLIN in varying networking scenarios where nodes communicate through two acoustic modems with widely different characteristics. MARLIN is compared to state-of-the-art forwarding protocols, including a channel-aware solution, a machine learning-based solution and to a flooding protocol extended to use multiple modems. Our results show that a smartly learned selection of relay and modem is key to obtain a packet delivery ratio that is twice as much that of other protocols, while maintaining low latencies and energy consumption

MARLIN-Q: multi-modal communications for reliable and low-latency underwater data delivery

This paper explores the smart exploitation of multi-modal communication capabilities of underwater nodes to enable reliable and swift underwater networking. Following a model-based reinforcement learning approach, we define a framework allowing senders to select the best forwarding relay for its data jointly with the best communication device to reach that relay. The choice is also driven by the quality of the communication to neighboring nodes over time, thus allowing nodes to adapt to the highly adverse and swiftly varying conditions of the underwater channel. The resulting forwarding method allows applications to choose among different classes of soft Quality of Service (QoS), favoring, for instance, reliable routes to the destination, or seeking faster packet delivery. We name our forwarding method MARLIN-Q, for Multi-modAl Reinforcement Learning-based RoutINg with soft QoS. We evaluate the performance of MARLIN-Q in varying networking scenarios where nodes communicate through two acoustic modems with widely different characteristics. MARLIN-Q is compared to state-of-the-art forwarding protocols, including a channel-aware solution, and a machine learning-based solution. Our results show that a smartly learned selection of relay and modem is key to obtain a packet delivery ratio that is twice as much that of other protocols, while maintaining low latency and energy consumption

Localizing Autonomous Underwater Vehicles: Experimental Evaluation of a Long Baseline Method

This work concerns underwater networking with mobile assets, like Autonomous Underwater Vehicles (AUVs), for advanced monitoring and exploration of submerged environments. Particularly, we are interested in enabling an AUV to localize itself while moving underwater by acoustically polling beacon nodes statically deployed at well-known location. Our method only relies on a model of the AUV dynamics, on an on-board depth sensor and on long baseline ranging information. The AUV applies an Extended Kalman Filter to estimate its position, without needing any further local measurements but those of depths. We have evaluated the accuracy of the proposed method via experiments at sea in the shallow waters around the Italian island of Ponza, computing the average distance between the estimated locations of the AUV and its positions as measured by GPS along its trajectory (localization error). In deployments with up to four beacons, our simple method enables AUVs to swiftly self localize with errors never exceeding 3.62m (using only two beacons), 2.65m (three beacons) and 2.45m (four beacons)

Maximizing The Value Of Sensed Information In Underwater Wireless Sensor Networks Via An Autonomous Underwater Vehicle

This paper considers underwater wireless sensor networks (UWSNs) for submarine surveillance and monitoring. Nodes produce data with an associated value, decaying in time. An autonomous underwater vehicle (AUV) is sent to retrieve information from the nodes, through optical communication, and periodically emerges to deliver the collected data to a sink, located on the surface or onshore. Our objective is to determine a collection path for the AUV so that the Value of Information (VoI) of the data delivered to the sink is maximized. To this purpose, we first define an Integer Linear Programming (ILP) model for path planning that considers realistic data communication rates, distances, and surfacing constraints. We then define the first heuristic for path finding that is adaptive to the occurrence of new events, relying only on acoustic communication for exchanging short control messages. Our Greedy and Adaptive AUV Path-finding (GAAP) heuristic drives the AUV to collect packets from nodes to maximize the VoI of the delivered data. We compare the VoI of data obtained by running the optimum solution derived by the ILP model to that obtained from running GAAP over UWSNs with realistic and desirable size. In our experiments GAAP consistently delivers more than 80% of the theoretical maximum VoI determined by the ILP model. © 2014 IEEE

SecFUN: Security framework for underwater acoustic sensor networks

In this paper we introduce SecFUN, a security framework for underwater acoustic sensor networks (UASNs). Despite the increasing interest on UASNs, solutions to secure protocols from the network layer up to the application layer are still overlooked. The aim of this work is therefore manyfold. We first discuss common threats and countermeasures for UASNs. Then, we select the most effective cryptographic primitives to build our security framework (SecFUN). We show that SecFUN is flexible and configurable with different features and security levels to satisfy UASN deployment security requirements. SecFUN provides data confidentiality, integrity, authentication and non-repudiation by exploiting as building blocks AES in the Galois Counter Mode (GCM) and short digital signature algorithms. As a proof of concept of the proposed approach, we extend the implementation of the Channel-Aware Routing Protocol (CARP) to support the proposed cryptographic primitives. Finally, we run a performance evaluation of our proposed secure version of CARP in terms of the overall energy consumption and latency, employing GCM and the state of the art in short digital signature schemes such as ZSS, BLS and Quartz. Results show that a flexible and full-fledged security solution tailored to meet the requirements of UASNs can be provided at reasonable costs. © 2015 IEEE