Runtime data center temperature prediction using Grammatical Evolution techniques

Depto. de Arquitectura de Computadores y AutomáticaFac. de InformáticaTRUEMinisterio de Economía y Competitividad (MINECO)pu

Generic Markov Model of the Contention Access Period of IEEE 802.15.4 MAC Layer

The IEEE-802.15.4 standard is poised to become the global standard for low data rate, low energy consumption Wireless Sensor Networks. By assigning the same sets of contention access parameters for all data frames and nodes, the Contention Access Period (CAP) of the slotted IEEE-802.15.4 currently provides an even channel access functionality and no service differentiation. However, some applications may require service differentiation and traffic prioritization support to accommodate high-priority traffic (e.g., alarms). In order to simulate a scenario in which different sets of access parameters for different node classes can be configured, this paper develops a Markov-chainbased model of the CAP of the IEEE-802.15.4-MAC. Our Markov model can be used to evaluate the impact of mixing node classes in important factors like the throughput, energy consumption, probability of delivery and the packet latency. The model has been used to provide traffic differentiation in a high saturation scenario in which a set of nodes can be configured to increase 76% the probability of sending a packet and reduce 58% latency, with a 69% energy penalty, in comparison with a standard scenario. The accuracy of the Markov model is validated by extensive ns-2 simulations

Arquitecturas dinámica de redes inalámbricas en banda libre para la ejemplificación de conceptos de transmisión en aplicaciones de “Internet Of Things”

Este proyecto de innovación educativa propone una metodología práctica y un equipamiento novedoso para la docencia de la asignatura de Redes y Servicios de Telecomunicación II impartida en tercer curso del Grado en Ingeniería Electrónica de Comunicaciones. Mediante la incorporación de elementos prácticos a la docencia como los recogidos en este proyecto, se pretende ahondar en los conceptos de uso espectral, acceso a un canal compartido, enrutamiento, topología de red, relación consumo vs. potencia de transmisión, etc. desde una perspectiva práctica que facilite el aprendizaje y despierte la curiosidad del alumnado. Para ello, se propondrá un despliegue de nodos inalámbricos, y un entorno de programación de éstos, que permita la evaluación de los contenidos antes descritos

Low Cost Software Receiver and Computerized Interface for the Practical Study of the Radioelectric Communications

En este proyecto se ha desarrollado una plataforma de bajo coste de Software Defined Radio (SDR, Receptor Radio Software) que consta de una componente hardware y otra software, ambas libres. El uso de la interfaz software nos ha permitido modificar distintos parámetros de transmisión de la señal (filtrado de armónicos, frecuencia de muestreo, demodulador, etc.) y estudiar su impacto en la calidad de la señal mediante la síntesis audible a través del altavoz del PC.In this project, a low cost Software Defined Radio (SDR) platform has been developed. This platform consists of a hardware component and a software one, being both of them GNU. The use of the software interface has allowed us to modify several signal transmission parameters (harmonic filtering, sampling rate, demodulation, etc.) and study their impact over the signal quality, thanks to the audio synthesis through the PC loudspeaker.Depto. de Arquitectura de Computadores y AutomáticaFac. de InformáticaFALSEsubmitte

Improving Circuit Performance with Multispeculative Additive Trees in High-Level Synthesis

The recent introduction of Variable Latency Functional Units (VLFUs) has broadened the design space of HighLevel Synthesis (HLS). Nevertheless their use is restricted to only few operators in the datapaths because the number of cases to control grows exponentially. In this work an instance of VLFUs is described, and based on its structure, the average latency of tree structures is improved. Multispeculative Functional Units (MSFUs) are arithmetic Functional Units that operate using several predictors for the carry signal. In spite of utilizing more than a predictor, none or only one additional very short cycle is enough for producing the correct result in the majority of the cases. In this paper our proposal takes advantage of multispeculation in order to increase the performance of tree structures with a negligible area penalty. By judiciously introducing these structures into computation trees, it will only be necessary to predict the carry signals in certain selected nodes, thus minimizing the total number of predictions and the number of operations that can potentially mispredict. Hence, the average latency will be diminished and thus performance will be increased. Our experiments show that it is possible to improve 26% execution time. Furthermore, our flow outperforms previous approaches with Speculative FUs

Reconsidering the performance of DEVS modeling and simulation environments using the DEVStone benchmark

The discrete event system specification formalism, which supports hierarchical and modular model composition, has been widely used to understand, analyze and develop a variety of systems. Discrete event system specification has been implemented in various languages and platforms over the years. The DEVStone benchmark was conceived to generate a set of models with varied structure and behavior, and to automate the evaluation of the performance of discrete event system specification-based simulators. However, DEVStone is still in a preliminary phase and more model analysis is required. In this paper, we revisit DEVStone introducing new equations to compute the number of events triggered. We also introduce a new benchmark with a similar central processing unit and memory requirements to the most complex benchmark in DEVStone, but with an easier implementation and with it being more manageable analytically. Finally, we compare both the performance and memory footprint of five different discrete event system specification simulators in two different hardware platforms

HackRF+GNU Radio: A software-defined radio to teach communication theory

In this paper, an alternative to the traditional methodology related to signal processing-like subjects is proposed. These are subjects that require a deep mathematical and theoretical basis, but the practical goal is not often emphasized, which drives students to lose interest in the subject. Thus, a software-defined radio environment is proposed to provide a more practical view of the subject. This solution consists of an open hardware?software platform able to capture and process a wide range of frequencies. HackRF is the hardware compo- nent, while GNU Radio will provide the graphical support to this device. The tests per- formed with a set of 36 students have revealed that they are more satisfied with this framework than just employing a traditional equation-based environment as Matlab. Furthermore, their scores in the exams also support the suitability of the proposed platform