Edson L. Ursini

Simulation inspired model for energy consumption in 3G always-on mobiles

Mobile devices that are permanently connected to IP networks are prone to have higher energy consumptions because unsolicited packets also force the device to move to a state where the consumption is higher. We consider a simplified model for the energy consumption based on the average consumptions in the different states and the time the device stays in each state. We perform discrete event simulations to obtain the energy consumption for different traffic scenarios and the simulation results are then fitted with simple models. We find that they give a relatively good description of the energy consumption behavior as a function of the T2 timer. Also, our results are consistent with measurements of the energy consumption for a mobile device connected to 3G networks with high or low data traffic profile.

Simulation of AdHoc Networks Including Clustering and Mobility

We introduce a discrete-event simulation model of an AdHoc network considering the presence of clusters and node mobility. The main goal is to study the volume of traffic in relatively large networks of sensor systems and Internet of Things considering fading and network connectivity. We also evaluate relevant parameters such as the mean CPU utilization and the mean queueing time in each node. The model is relatively general in that it combines the traffic from small devices such as sensors as well as more complex intermediate systems such as gateways and Internet nodes. It is also extensible to other types of scenarios and it allows the evaluation of the network under other performance criteria or evaluation metrics. The results show that the model yields simulation values that could be analytically validated by Jackson networks.

n-Steps ahead software reliability prediction using the Kalman filter

This paper presents KSL, a new software reliability growth model (SRGM) based on the Kalman filter with a sub filter and the Laplace trend test. We applied the model to the Linux operating system kernel as a case study to predict the absolute and relative (per lines of code) number of faults n-steps ahead. The Laplace trend test is applied to detect when the series no longer follows a homogeneous Poisson process, improving the confidence level. An example is provided with a prediction of 13months ahead on the number of faults with 8% error. The results (i.e. predictive capability) indicated that the proposed approach outperforms the S-shaped prediction model, Weibull, and Exponentiated Weibull distributions, as well as typical and OS-ELM Neural networks when the series has a short number of observations.

A Bullying-Severity Identifier Framework Based on Machine Learning and Fuzzy Logic

Bullying at schools is a serious social phenomenon around the world that negatively affects the development of children. However, anti-bullying programs should not focus on labeling children as either bullies or victims since they could produce opposite effects. Thus, an approach to deal with bullying episodes, without labeling children, is to determine their severity, so that school staff may respond to them appropriately. Related work about computational techniques to fight against bullying showed promising results but they offer categorical information as a set of labels. This work proposes a framework to determine bullying severity in texts, composed by two parts: (1) evaluation of texts using Support Vector Machine (SVM) classifiers found in the literature, and (2) development of a Fuzzy Logic System that uses the outputs of SVM classifiers as its inputs to identify the bullying severity. Results show that it is necessary to improve the accuracy of SVM classifiers to determine the bullying severity through Fuzzy Logic.

Evaluation of Traffic Delays and Utilization of IoT Networks Considering Mobility

The performance analysis and dimensioning of an IoT network is presented, using discrete-event simulation and considering node mobility. Specifically, the processor utilization on each node and the mean-time delay of the network are estimated. Additionally, given that the lower the transmission power the larger may be the packet loss, and that the tolerance to the amount of packet loss depends on the application, the simulated IoT network may provide the designer with a guideline to specify the minimum required transmission power as a function of node distance and admissible packet loss. This lower threshold on transmission power is critical, since in wireless and battery-powered systems, the transmission power has a direct impact on its expected lifespan.

Blocking of the Cell Overflow Traffic in Heterogeneous Networks

The fifth generation of wireless networks, or 5G as it is known, will allow a radical re-evaluation on the performance of mobile telecommunication services as well as it will support new and important applications such as enhanced mobile broadband, high mobility cases (planes, trains, etc.), Internet of things, smart cities, drones, robotics, etc. The objective of this work is to research, by means of simulation experiments, the network performance of the handover procedures under traffic variation and at different deployment scenarios of wireless applications, aiming to derive core network planning instructions. The used methodology is based on the principle of incremental validation, in which, in a first step, simplified analytical and/or simulation models are enhanced and validated by comparison with real situations or analytical solutions. Then, by means of increments in the complexity of the distributions and/or new functionalities, and with the increase of the knowledge of the problem, the dimensioning solution is refined.

Internet of Things: An Overview of Architecture, Models, Technologies, Protocols and Applications

The Internet has established itself as a network and international communication medium, thus allowing people, computers and machines to communicate. The reduction in costs and size of interfaces that access the Internet allowed common devices (e.g. appliances, air conditioners, alarm systems and lighting) the access to a wide network. In a short time, the Internet of Things emerged, allowing the connection of an increasing number of intelligent devices from diverse fields of the economy. The growing application of IoT must be well understood, due to its potential to increase and use data in real-time, and the abundance of information available from sensors. Within this context, this work contributes with an updated overview of this new network environment in relation to its architecture, models, technologies, protocols and applications.

Minimizing the mode-change latency in real-time image processing applications

Modes of operation and mode changes are a useful abstraction to allow configurable real-time systems. Substantial work on the fixed priority preemptive scheduling approach allowed tasks across a mode change to be provided with real-time guarantees. However, the proper configuration of critical parameters such as task’s offsets, despite initial work, remains lacking in the research. Without a method that automates this design step, while assuring that the basic requirements are met, the full adoption of mode changes in real-time systems remains limited to relatively simple systems with limited task sets. In this work, we propose a method to assign offsets to tasks across a mode change that is able to minimize the latency of a mode change using genetic algorithms. Through a number of case studies, using an image-processing application as an example, we both validate the approach as well as show that the method is flexible in that it can accommodate other requirements, such as the minimization of offsets.

Modeling and simulation applied to link dimensioning of stream IP traffic with incremental validation

Modern networks for converged services (voice, video and data) require appropriate planning and dimensioning. In this paper, we present a methodology for dimensioning the link capacity and packet delay in stream, IP multi-service networks with QoS requirements, in which discrete-event simulation is essential. The model may be used in the lack of enough reliable real-world data, since it is initially validated by an analytical model and then augmented step by step. The approach can be made more reliable if measured values are used. We show that the incremental approach allows a significant reduction in simulation time without significant loss of accuracy, by exploiting the sample variance reduction due to the large difference in the time scale between events occurring in the application (service layer) and in the packet layer. We demonstrated the applicability of this method with typical multi-service network scenarios.

Encaminhamento seletivo de pacotes provido por um Gateway Multimídia baseado em IP

Este artigo descreve os resultados pertinentes ao mecanismo de encaminhamento seletivo de pacotes provido por um gateway multimidia baseado em IP para os servicos multimidia de audio, voz, video e dados. Sua estrutura funcional esta embasada nos campos ToS e TC dos protocolos IPv4 e IPv6, tidos como DSCP e ECN, e possibilita sua utilizacao em ambientes de rede variados, fornecendo recursos para inspecao, processamento e encaminhamento seletivo de pacotes IP, dentre outros. Seus resultados satisfatorios possibilitam e viabilizam sua utilizacao como ferramenta complementar no estudo e analise de solucoes voltadas as redes multimidia, de modo geral. Este artigo descreve os resultados pertinentes ao mecanismo de encaminhamento seletivo de pacotes provido por um gateway multimidia baseado em IP para os servicos multimidia de audio, voz, video e dados. Sua estrutura funcional esta embasada nos campos ToS e TC dos protocolos IPv4 e IPv6, tidos como DSCP e ECN, e possibilita sua utilizacao em ambientes de rede variados, fornecendo recursos para inspecao, processamento e encaminhamento seletivo de pacotes IP, dentre outros. Seus resultados satisfatorios possibilitam e viabilizam sua utilizacao como ferramenta complementar no estudo e analise de solucoes voltadas as redes multimidia, de modo geral.