Search results for "Wireless"
showing 10 items of 879 documents
A flexible and tunable route discovery mechanism for on-demand protocols
2004
Mobile ad-hoc networks are characterized by multihop wireless links and absence of cellular infrastructure. For the last years, routing has been the area under most intensive research. In particular, on-demand routing protocols proposed are extremely attractive due to their low-overhead and efficiency. Currently, wireless ad-hoc networks lack multipath routing protocols. Multipath routing enables increased QoS support, load balancing and enhanced route stability. In this paper we present a new route discovery solution that increases the number of routes found, while reducing the routing overhead when compared to previous proposals. Simulation results show that the additional routing overhea…
Experimental Characterization of a Double Receiver Dynamic Wireless Charging System
2020
The aim of this work is the characterization of a dynamic wireless charging system low power prototype and the validation of a simplified mathematical model of the employed double D coils. The difference between a single receiver and a dual receiver system is also shown, highlighting how the last one can significantly reduce the costs of the charging infrastructure.
Wearable photoplethysmography device prototype for wireless cardiovascular monitoring
2014
The aim of the study was to develop a prototype system of the smart garment for real time telemetric monitoring of human cardiovascular activity. Two types of photoplethysmography (PPG) sensors for low noise and artefact free signal recording from various sites of the human body that were suitable for integration into smart textile were investigated. The reflectance sensors with single and multiple photodiodes based on "pulse-duration-based signal conversion" signal acquisition principle were designed and evaluated. The technical parameters of the system were measured both on bench and in vivo. Overall, both types of PPG sensors showed acceptable signal quality SNR 86.56±3.00 dB, dynamic ra…
The MOBI-Kids Study Protocol: Challenges in Assessing Childhood and Adolescent Exposure to Electromagnetic Fields from Wireless Telecommunication Tec…
2014
The rapid increase in mobile phone use in young people has generated concern about possible health effects of exposure to radiofrequency (RF) and extremely low frequency (ELF) electromagnetic fields (EMF). MOBI-Kids, a multinational case–control study, investigates the potential effects of childhood and adolescent exposure to EMF from mobile communications technologies on brain tumor risk in 14 countries. The study, which aims to include approximately 1,000 brain tumor cases aged 10–24 years and two individually matched controls for each case, follows a common protocol and builds upon the methodological experience of the INTERPHONE study. The design and conduct of a study on EMF exposure an…
Compression Methods for Microclimate Data Based on Linear Approximation of Sensor Data
2019
Edge computing is currently one of the main research topics in the field of Internet of Things. Edge computing requires lightweight and computationally simple algorithms for sensor data analytics. Sensing edge devices are often battery powered and have a wireless connection. In designing edge devices the energy efficiency needs to be taken into account. Pre-processing the data locally in the edge device reduces the amount of data and thus decreases the energy consumption of wireless data transmission. Sensor data compression algorithms presented in this paper are mainly based on data linearity. Microclimate data is near linear in short time window and thus simple linear approximation based …
Practical procedure for verification of compliance of digital mobile radio base stations to limitations of exposure of the general public to electrom…
2002
In the last few years, society has witnessed the installation of an ever increasing number of radio base stations as a necessity for handling new capabilities and services to the large number of users. This rapid development of wireless networks, however, has induced a marked mistrustful attitude in people, who fear possible biological effects of electromagnetic emissions from mobile communications base stations. While there are guidelines on the limitation of human exposure to electromagnetic fields (emf ), there is no harmonised standard measurement procedure to evaluate compliance with the limits on exposure in the vicinity of a base station. The measurement procedure has to be practical…
Ant colony optimisation for planning safe escape routes
2013
Published version of a chapter from the volume: Recent Trends in Applied Artificial Intelligence. Also available on SpringerLink: http://dx.doi.org/10.1007/978-3-642-38577-3_6 An emergency requiring evacuation is a chaotic event filled with uncertainties both for the people affected and rescuers. The evacuees are often left to themselves for navigation to the escape area. The chaotic situation increases when a predefined escape route is blocked by a hazard, and there is a need to re-think which escape route is safest. This paper addresses automatically finding the safest escape route in emergency situations in large buildings or ships with imperfect knowledge of the hazards. The proposed so…
Evaluating the Performance of Real Time Videoconferencing in Ad Hoc Networks Through Emulation
2008
The validation of new video protocols and applications for mobile ad hoc networks in a real environment is an important task. In this work we present Castadiva, a test-bed architecture that allows validating software solutions for ad hoc networks using low-cost, off-the-shelf devices and open source software. We use this tool to test a videocall using the OLSR protocol in different scenarios, varying the number of hops between the caller and the receiver. The results obtained in this paper show that, for an ad hoc network with a large number of hops, the quality of videocalls suffers a significant degradation even in the absence of mobility.
Analysis of Energy Consumption Performance towards Optimal Radioplanning of Wireless Sensor Networks in Heterogeneous Indoor Environments
2014
In this paper the impact of complex indoor environment in the deployment and energy consumption of a wireless sensor network infrastructure is analyzed. The variable nature of the radio channel is analyzed by means of deterministic in-house 3D ray launching simulation of an indoor scenario, in which wireless sensors, based on an in-house CyFi implementation, typically used for environmental monitoring, are located. Received signal power and current consumption measurement results of the in-house designed wireless motes have been obtained, stating that adequate consideration of the network topology and morphology lead to optimal performance and power consumption reduction. The use of radiopl…
Novel Energy Efficient Schemes for Wireless Sensor Networks Utilizing Mobile Sensors
2022
Wireless sensor networks (WSNs) facilitate many applications in different fields and are well-known in both academic and industrial areas. The networks mainly include sensors, networking parts and a data processing center to collect data for a variety of purposes. However, the energy consumption problem in the networks is always a critical problem that many researchers are looking for good solutions. In this paper, we propose a data collection method that uses mobile sensors attached with bigger energy storages to collect data from static sensors. In addition, we propose a hybrid energy harvesting scheme to harvest energy from ambient environments to support static sensors to prolong the ne…