Thesis Proposal: Methodology for Implementation of Synchronization Strategies for Wireless Sensor Networks
Posted on by frta

 

Author: Francisco Tirado-Andrés

Advisor: Alvaro Araujo Pinto

Synopsis:
Wireless Sensor Networks (WSN) are networks composed of a large number of small devices that take measurements, process them, and communicate with other devices coordinating their operations. Time synchronization is necessary for that coordination of actions.

Multiple features characterized a WSN. Some of them are Power Consumption, Cost, Network type, Security, Data throughput, Scalability, etc.

WSNs bring us many benefits over traditional wired networks, but they also add difficulties to counteract its limitations.

The functionality of a WSN is very specific to the problem it solves. It is therefore that no single synchronization method is optimal along all axes. Unnecessary synchronization wastes resources; insufficient synchronization leads to poor application performance.

The requirements that are entailed to the various parameters that define the synchronization protocol will come imposed by the specific application to which it is oriented.

Because, it is not the same an application for a distributed humidity control in a natural park where each sample is collected every half hour and synchronization may deviate seconds without affecting the results, that the conditions required for an application of Wireless Surround Sound System where real-time operations and very small deviations are needed for a proper operation of the system.

But today there is no methodology that helps to design or configuration. Neither with the synchronization protocols nor the general system parameters.

There are many difficulties to be resolved because the synchronization protocol must meet not only the requirements of the application for which is designed, but also the intrinsic demands of WSNs.

One application where the results are very dependent on the accuracy of timing synchronization is Structural Health Monitoring (SHM). A configurable protocol which is able to adapt itself to the requirements of the application and the requirements of the system will be more useful and it will be ready for future applications and requirements.

My intention is to contribute, both during, and at the end of this thesis, with a methodology to guide and help implement synchronization protocols in Wireless Sensor Networks. Always keeping in mind that the synchronization protocol must meet requirements of accuracy and precision at the same time should not interfere with the performance of other tasks in the system. In that way the user will be able to adapt the configuration of the system and the parameters to get a productive WSN.

BackToTheFuture-Synchronization
Movie: Back To the Future. 23’17”

Nuevos diseños de antenas microstrip para las bandas ISM.
Posted on by Gis

 

Debido a la evolución y nuevos usos de la microelectrónica, la miniaturización de los dispositivos electrónicos cada vez es mayor.

Esto presenta un problema a la hora de usar antenas convencionales, que suelen ser de tamaños mucho mayor que el resto de dispositivos de la placa que va a transmitir.

Por ello, se usan las antenas microstrip. Son un tipo de antena de bajo coste de realización y pequeño tamaño la cual se implementa directamente sobre la misma PCB.

Actualmente se lleva a cabo un trabajo de investigación con estas antenas en el B105, para proceder a su estudio y caracterización. Para ello, se han realizado simulaciones de antenas loop y semiloop sintonizadas a 433MHz.  Estas antenas van a ser implementadas en las próximas semanas, ya que han demostrado buena eficiencia con un tamaño muy reducido.

 

Sin título

Thesis: Software-Defined Radio Techniques for Resource Optimization in Cognitive Wireless Sensor Networks
Posted on by Ramiro Utrilla

Author: Ramiro Utrilla Gutiérrez

Advisor: Alvaro Araujo Pinto

Synopsis: Due to the spectrum scarcity problem, mostly in license-free ISM bands, and the forecasts regarding the increasing adoption of wireless communications, especially in scenarios like cities, it is essential to optimize the use of the spectrum to ensure the proper functioning of services and devices in the near future.

As the characteristics of the spectrum, by their own physical nature and its use, are very dynamic and vary constantly, devices must be able to intelligently adapt to these changes, as the Cognitive Radio paradigm proposes. Moreover, this adaptation should be done quickly in order to be effective and it should minimize the impact on the use of the spectrum.

Because of that, this work is going to be mainly focused on the development and evaluation of cognitive strategies with zero or minimum communication overhead. In other words, the aim of the research is to evaluate the degree of optimization of resources that can be achieved in a Cognitive Wireless Sensor Network (CWSN) by doing the cognitive cycle (spectrum sensing, learning and adaptation) mostly at node-level. To better exploit the cognitive radio capabilities of these networks, and thanks to the current development of wireless and processing technology, Software-Defined Radio (SDR) techniques are going to be used in sensor nodes for that purpose. This approach supposes a new paradigm in CWSNs which implies new challenges to be faced.

At this point, it appears to be necessary to evaluate some issues about the future of wireless communications. Will someday the need for cognition to use the spectrum outweigh the current energy constraints? In other words, will it be possible to achieve efficient and reliable wireless communication without cognitive capabilities in the near future? Answering this question will reveal whether it still make sense to compare the power consumption of SDR solutions with other platforms based on COTS radio transceivers or, conversely, the addition of cognitive capabilities will cease to pose a challenge to maximize systems’ efficiency and become a key point for their proper operation.

 

ContikiHUB
Posted on by b105

Las Redes de Sensores Inalámbricas (WSN por su nombre en inglés, Wireless Sensor Networks) se encuentran en una fase de rápida expansión por su gran valor en aplicacionescomo la domótica, seguridad o la gestión de recursos en el ámbito industrial. Continuando con la línea de investigación en sistemas operativos (OS) para redes de este tipo recientemente iniciada en el laboratorio, hemos decidido realizar un proyecto que resultará de enorme utilidad a la hora de iniciar el despliegue de una WSN.

ContikiHUB es una plataforma que actúa como pasarela entre los nodos de una WSN que implemente el sistema operativo Contiki e internet. Dado que una WSN emplea distintos protocolos de comunicaciones y medios físicos que los de una red clásica de internet, el objetivo es el de diseñar un hardware capaz de adaptar esos medios físicos para que puedan interconectarse, a la vez que trabajar en el sistema operativo para hacerlo totalmente funcional en dicho hardware y lograr que los protocolos para WSN que utiliza Contiki sean compatibles con los que se emplean en internet.

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De esta forma, el resultado final será una plataforma capaz de integrarse por un lado en una WSN (actuando como nodo si es preciso gracias a varios puertos de expansión donde podrán conectarse diversos tipos de sensores) y por otro con un router de una red de internet, pudiendo enviar y recibir datos libremente entre ambas redes.

Thesis: Operating Systems dynamic optimization for Wireless Sensor Networks
Posted on by Roberto Rodríguez

Author: Roberto Rodriguez-Zurrunero

Advisor: Alvaro Araujo Pinto

Synopsis:  Wireless Sensor Networks are composed by multiple tiny nodes with limited resources. It is very important to manage the nodes operation as best as possible. This way it could be possible to improve the global performance with these limited resources. Therefore, an Operating System (OS) may be used to control the hardware and provide hardware abstraction to applications. The basic functionalities of an OS include resource abstractions for various hardware devices, interrupt management, task scheduling, concurrency control, and networking support. With these OS services the developers may program high-level applications independent of the underlying hardware and improving the nodes management. A traditional OS could not be embedded on WSN because they are used on systems with plenty of resources and different requirements. In WSN the resources are limited so an OS should manage them the best possible and it should involve the less overload possible in memory and CPU usage.

This thesis deals with the OS for WSN field. The goal is to take advantage of dynamic optimization of OS to improve some specific WSN parameter such as energy efficiency, processing capacity, flexibility, reliability, security and networking.