P. Yuste

Bio: P. Yuste is an academic researcher from Polytechnic University of Valencia. The author has contributed to research in topics: Wireless sensor network & Underwater acoustic communication. The author has an hindex of 8, co-authored 21 publications receiving 277 citations. Previous affiliations of P. Yuste include University of Valencia.

A low cost and high efficient acoustic modem for underwater sensor networks

Abstract: Underwater wireless sensor Networks (UWSN) will provide a variety of attractive working fields such as aquaculture, offshore exploitation, biological monitoring as well as water and seafloor pollution, seismic activity and ocean currents. A practical implementation of these applications will require spreading an important number of nodes to facilitate underwater monitoring by means of data acquiring, so it becomes a challenge to develop simple and reliable modem architectures to reduce both the cost in components and the developing time, still being efficient and robust. Moreover power consumption must be also considered due to energy harvesting difficulties in an underwater environment. This work is focused in the design and implementation of a low cost and energy efficient underwater modem. The paper presents a new acoustic modem design based on an original signal-conditioning model optimally adapted to commercial echo sounder based piezoelectric transducers. It represents a very low-cost solution with a power consumption level similar to current terrestrial wireless sensor networks. The modulation and demodulation algorithms are essential to define the modem architecture. In this work, they have been adapted to a low power microcontroller processing capabilities. The proposed modem architecture includes an 8-bit microcontroller and few external analog components. A binary Coherent-FSK modulation has been chosen because it is more efficient in terms of bandwidth than a non-coherent FSK. Coherent FSK modulation algorithm is quite simple, and can be easily implemented in an 8-bit microcontroller with negligible execution time. Demodulation algorithm is more complex and needs a low-power solution. The paper investigates different alternatives, obtaining a new optimal solution including an additional specific processing unit to the microprocessor core. Compared with previous researches that used microcontrollers, the presented approach also improves energy efficiency without lowering bit rate and bandwidth efficiency. The design has a variable gain reception to measure precisely the incoming signal level and obtaining signal quality indicators similar to RSSI used in wireless RF sensor networks. The circuit has been simulated and experimentally tested too with a prototype. Several tests have been carried out using the different alternatives presented. The goal of the first experiments was to characterize the frequency response of the transducers, and validate acoustic wave generation and amplification models obtained by means of simulation. Measurements were also taken to obtain receiver sensitivity and communication efficiency to power variations. Efficient design of both power amplifier and receiver analog processing stages, combined with optimal microcontroller power saving modes has extended estimated battery. As a conclusion, a worthwhile modem has been designed with the following advantages: Ultra-Low power consumption, a small form factor and a low final cost which enable future low cost deployment of underwater sensor networks.

An ultra-low power and flexible acoustic modem design to develop energy-efficient underwater sensor networks.

Abstract: This paper is focused on the description of the physical layer of a new acoustic modem called ITACA. The modem architecture includes as a major novelty an ultra-low power asynchronous wake-up system implementation for underwater acoustic transmission that is based on a low-cost off-the-shelf RFID peripheral integrated circuit. This feature enables a reduced power dissipation of 10 µW in stand-by mode and registers very low power values during reception and transmission. The modem also incorporates clear channel assessment (CCA) to support CSMA-based medium access control (MAC) layer protocols. The design is part of a compact platform for a long-life short/medium range underwater wireless sensor network.

Non-intrusive Software-Implemented Fault Injection in Embedded Systems

Abstract: Critical embedded systems, like those used in avionics or automotive, have strong dependability requirements and most of them must face with fault tolerance. One of the methods typically used to validate fault tolerance mechanisms is fault injection. The idea is to study the behavior of the system in presence of faults in order to determine whether the system behaves properly or not. Software-implemented fault injection (SWIFI) techniques enable fault injection to be performed by software. Although interesting, major drawbacks of existing SWIFI techniques are the temporal and the spatial overheads they induced in the systems under study. The reduction of these overheads is thus crucial, in order to be confident on the results and conclusions of a SWIFI experiment. This paper focuses on this problem. It proposes a new non-intrusive SWIFI technique for injecting faults in embedded (system-on-chip) applications. The technique exploits the features of a standard debugging interface for embedded systems, called Nexus, in order to inject faults without temporal overhead. Then, Nexus features are also exploited in order to observe, without spatial intrusion, the behavior of the target system in presence of the injected faults. In other words, the embedded system under study can be controlled (for injecting faults) and observed (for tracing its behavior) without customizing its original structure or altering its normal execution. Since based on Nexus, the technique has also the benefit of being applicable to any Nexus-compliant system. In order to illustrate the potentials of the approach, we use an automotive embedded control unit application as a case study. Some preliminary results obtained from the experiments performed are also discussed.

On benchmarking the dependability of automotive engine control applications

Abstract: The pervasive use of ECUs (electronic control units) in automotive systems motivates the interest of the community in methodologies for quantifying their dependability in a reproducible and cost-effective way. Although the core of modern vehicle engines is managed by the control software embedded in engine ECUs, no practical approach has been proposed so far to characterise the impact of faults on the behaviour of this software. This paper proposes a dependability benchmark for engine control applications. The essential features of such type of applications are first captured in a general model, which is then exploited in order to specify a standard procedure to assess dependability measures. These measures are defined taking into account the expectations of industrials purchasing engine ECUs with integration purposes. The benchmark also considers the current set of technological limitations that the manufacturing of modern engine ECUs imposes to the experimental process. The approach is exemplified on two engine control applications.

INERTE: integrated nexus-based real-time fault injection tool for embedded systems

Abstract: Software implemented fault injection techniques (SWIFI) enable emulation of hardware and software faults. This emulation can be based on debugging mechanisms of general purpose processors [1] or in special debugging ports of embedded processors [2]. A well-known drawback of existing SWIFI tools rely on the temporal overhead introduced in the target system. This overhead is a problem when validating real-time systems. This paper presents a new SWIFI tool (INERTE) that solves this problem by using a standard debug interface called Nexus [3]. Using Nexus, system memory can be accessed at runtime without any intrusion in the target system. Thus, INERTE is able to inject transient faults without any temporal overhead.

Exploration of underwater life with an acoustically controlled soft robotic fish

Abstract: Closeup exploration of underwater life requires new forms of interaction, using biomimetic creatures that are capable of agile swimming maneuvers, equipped with cameras, and supported by remote human operation. Current robotic prototypes do not provide adequate platforms for studying marine life in their natural habitats. This work presents the design, fabrication, control, and oceanic testing of a soft robotic fish that can swim in three dimensions to continuously record the aquatic life it is following or engaging. Using a miniaturized acoustic communication module, a diver can direct the fish by sending commands such as speed, turning angle, and dynamic vertical diving. This work builds on previous generations of robotic fish that were restricted to one plane in shallow water and lacked remote control. Experimental results gathered from tests along coral reefs in the Pacific Ocean show that the robotic fish can successfully navigate around aquatic life at depths ranging from 0 to 18 meters. Furthermore, our robotic fish exhibits a lifelike undulating tail motion enabled by a soft robotic actuator design that can potentially facilitate a more natural integration into the ocean environment. We believe that our study advances beyond what is currently achievable using traditional thruster-based and tethered autonomous underwater vehicles, demonstrating methods that can be used in the future for studying the interactions of aquatic life and ocean dynamics.

Underwater Acoustic Wireless Sensor Networks: Advances and Future Trends in Physical, MAC and Routing Layers

Abstract: This survey aims to provide a comprehensive overview of the current research on underwater wireless sensor networks, focusing on the lower layers of the communication stack, and envisions future trends and challenges. It analyzes the current state-of-the-art on the physical, medium access control and routing layers. It summarizes their security threads and surveys the currently proposed studies. Current envisioned niches for further advances in underwater networks research range from efficient, low-power algorithms and modulations to intelligent, energy-aware routing and medium access control protocols.

Ultra Low Power Wake-Up Radios: A Hardware and Networking Survey

Abstract: In wireless environments, transmission and reception costs dominate system power consumption, motivating research effort on new technologies capable of reducing the footprint of the radio, paving the way for the Internet of Things. The most important challenge is to reduce power consumption when receivers are idle, the so called idle-listening cost. One approach proposes switching off the main receiver, then introduces new wake-up circuitry capable of detecting an incoming transmission, optionally discriminating the packet destination using addressing, then switching on the main radio only when required. This wake-up receiver technology represents the ultimate frontier in low power radio communication. In this paper, we present a comprehensive literature review of the research progress in wake-up radio (WuR) hardware and relevant networking software. First, we present an overview of the WuR system architecture, including challenges to hardware design and a comparison of solutions presented throughout the last decade. Next, we present various medium access control and routing protocols as well as diverse ways to exploit WuRs, both as an extension of pre-existing systems and as a new concept to manage low-power networking.

Underwater Acoustic Modems

Abstract: Due to the growing interest using underwater acoustic networks, there are more and more research papers about underwater communications. These papers are mainly focused on deployments and studies about the constraints of the underwater medium. The underwater acoustic channel is highly variable and the signal transmission can change according to environmental factors, such as the temperature, pressure, or salinity of the water. For this reason, it is important to know how these devices are developed and the maximum distance and data transfer rates they can achieve. To this end, this paper presents an exhaustive study of existing underwater acoustic modems where their main features are highlighted. We also review the main features of their hardware. All presented proposals in the research literature are compared with commercial underwater acoustic modems. Finally, we analyze different programs and improvements of existing network simulators that are often used to simulate and estimate the behavior of underwater networks.