30 resultados para Smart meter, Microcontrollore, Wireless, Risparmio energetico, Domotica
Resumo:
This paper aims at illustrating some applications of Finite Random Set (FRS) theory to the design and analysis of wireless communication receivers, and at pointing out similarities and differences between this scenario and that pertaining to multi-target tracking, where the use of FRS has been traditionally advocated. Two case studies are considered, l.e., multiuser detection in a dynamic environment, and multicarrier (OFDM) transmission on a frequency-selective channel. Detector designand performance evaluation are discussed, along with the advantages of importing FRS-based estimation techniques to the context of wireless communications.
Resumo:
The optimization of the pilot overhead in wireless fading channels is investigated, and the dependence of this overhead on various system parameters of interest (e.g., fading rate, signal-to-noise ratio) is quantified. The achievable pilot-based spectral efficiency is expanded with respect to the fading rate about the no-fading point, which leads to an accurate order expansion for the pilot overhead. This expansion identifies that the pilot overhead, as well as the spectral efficiency penalty with respect to a reference system with genie-aided CSI (channel state information) at the receiver, depend on the square root of the normalized Doppler frequency. It is also shown that the widely-usedblock fading model is a special case of more accurate continuous fading models in terms of the achievable pilot-based spectral efficiency. Furthermore, it is established that the overhead optimization for multiantenna systems is effectively the same as for single-antenna systems with thenormalized Doppler frequency multiplied by the number of transmit antennas.
Resumo:
The purpose of this paper is to examine (1) some of the models commonly used to represent fading,and (2) the information-theoretic metrics most commonly used to evaluate performance over those models. We raise the question of whether these models and metrics remain adequate in light of the advances that wireless systems haveundergone over the last two decades. Weaknesses are pointedout, and ideas on possible fixes are put forth.
Resumo:
The advances of the semiconductor industry enable microelectromechanical systems sensors, signal conditioning logic and network access to be integrated into a smart sensor node. In this framework, a mixed-mode interface circuit for monolithically integrated gas sensor arrays was developed with high-level design techniques. This interface system includes analog electronics for inspection of up to four sensor arrays and digital logic for smart control and data communication. Although different design methodologies were used in the conception of the complete circuit, high-level synthesis tools and methodologies were crucial in speeding up the whole design cycle, enhancing reusability for future applications and producing a flexible and robust component.
Resumo:
The aim of this brief is to present an original design methodology that permits implementing latch-up-free smart power circuits on a very simple, cost-effective technology. The basic concept used for this purpose is letting float the wells of the MOS transistors most susceptible to initiate latch-up.
Resumo:
The application of adaptive antenna techniques to fixed-architecture base stations has been shown to offer wide-ranging benefits, including interference rejection capabilities or increased coverage and spectral efficiency.Unfortunately, the actual implementation ofthese techniques to mobile communication scenarios has traditionally been set back by two fundamental reasons. On one hand, the lack of flexibility of current transceiver architectures does not allow for the introduction of advanced add-on functionalities. On the other hand, theoften oversimplified models for the spatiotemporal characteristics of the radio communications channel generally give rise toperformance predictions that are, in practice, too optimistic. The advent of software radio architectures represents a big step toward theintroduction of advanced receive/transmitcapabilities. Thanks to their inherent flexibilityand robustness, software radio architecturesare the appropriate enabling technology for theimplementation of array processing techniques.Moreover, given the exponential progression ofcommunication standards in coexistence andtheir constant evolution, software reconfigurabilitywill probably soon become the only costefficientalternative for the transceiverupgrade. This article analyzes the requirementsfor the introduction of software radio techniquesand array processing architectures inmultistandard scenarios. It basically summarizesthe conclusions and results obtained withinthe ACTS project SUNBEAM,1 proposingalgorithms and analyzing the feasibility ofimplementation of innovative and softwarereconfigurablearray processing architectures inmultistandard settings.
Resumo:
Aim of this contribution is to illustrate the state of the art of smart antenna research from several perspectives. The bow is drawn from transmitter issues via channel measurements and modeling, receiver signal processing, network aspects, technological challenges towards first smart antenna applications and current status of standardization. Moreover, some future prospects of different disciplines in smart antenna research are given.
Resumo:
Trabajo de final de carrera enfocado a la simulación de una WSN (Wireless Sensors Networks) mediante el programa Contiki 2.7 y el SO Ubuntu. La idea global del proyecto es conseguir simular un entorno con nodos sensores y, a posteriori, comprobar su correcto funcionamiento en motas reales, comprobando los resultados obtenidos en ambos entornos. De esta manera se puede facilitar la puesta en marcha de este tipo de redes inalámbricas en una aplicación real.
Resumo:
Testbeds are a stage between the simulation and the production stages. To this end they must be as close as possible to production environments (i.e. real hardware, on the field deployments) while also keeping the traits of experimentation facilities (i.e. fault tolerance, ease of deployment, testing and data collection). This paper presents WiBed, a FOSS platform for WiFi testbeds based on OpenWRT Linux made to run oncommodity IEEE802.11 WiFi routers part of the Community-lab.net project, a global testbed for Community networks. WiBedhas been designed to support realistic low layer network exper-iments (according to the OSI model). This work recolects thedetails of the architecture, design and implementation of WiBed consolidated during its operation as a testbed. In addition to a set of routing experimentation results obtained during the Wireless Battlemesh v7 where WiBed was used as testbed platform.
Resumo:
Wireless Sensor Networks (WSN) are formed by nodes with limited computational and power resources. WSNs are finding an increasing number of applications, both civilian and military, most of which require security for the sensed data being collected by the base station from remote sensor nodes. In addition, when many sensor nodes transmit to the base station, the implosion problem arises. Providing security measures and implosion-resistance in a resource-limited environment is a real challenge. This article reviews the aggregation strategies proposed in the literature to handle the bandwidth and security problems related to many-to-one transmission in WSNs. Recent contributions to secure lossless many-to-one communication developed by the authors in the context of several Spanish-funded projects are surveyed. Ongoing work on the secure lossy many-to-one communication is also sketched.
Resumo:
This paper presents WiBed, a FOSS platform for WiFi testbeds based on OpenWRT Linux made to run on commodity IEEE802.11 WiFi routers part of the Community-lab.net project, a global testbed for Community networks. WiBed has been designed to support realistic low layer network experiments (according to the OSI model). This work recolects the details of the architecture, design and implementation of WiBed consolidated during its operation as a testbed.
Resumo:
Treball de final de carrera que consisteix en una aplicació per a mòbils que connecta el servei REST amb un servidor.
Resumo:
SOSoW (SOS Over Wireless) és una aplicació Android que ajuda a ser localitzat en situacions d'emergència extremes, fent ús únicament dels propis sensors de l'smartphone i sense necessitat d'internet ("offline").
Resumo:
The objective of this project was to develop firmware for both the Arduino-compatible boards of the Smart Citizen initiative, and for the RTX4100 low-power WiFi.
Resumo:
Análisis del origen del concepto de smart cities que deriva de la gestión y ahorro energético, comparación de ejemplos de smart cities actuales y realización de un caso práctico sobre Lima analizando exhaustivamente qué componentes tenemos según las diferentes métricas e indicadores y qué componentes faltarían para poder ser una ciudad "smart".