Search results for "Wireless"
showing 10 items of 879 documents
HQMR: Hybrid QoS based Routing Protocol for Wireless Mesh Environment
2015
International audience; Wireless Mesh Networks (WMNs) have been attracting more and more interest from both academic and industrial environments for their seamless broadband connectivity to Internet networks. Besides, providing QoS guarantees for real-time and streaming applications such as Voice over IP (VoIP) and Video on Demand (VoD) is a challenging issue in such environment. Thus, we propose a novel QoS based routing protocol for wireless mesh infrastructure, called Hybrid QoS Mesh Routing (HQMR). Moreover, a clustering algorithm is developed to enhance scalability issues within the mesh infrastructure. HQMR is composed of two routing sub-protocols: a reactive routing protocol for intr…
Target 5G visible light positioning signal subcarrier extraction method using particle swarm optimization algorithm
2021
International audience; With the explosive growth of demand for Internet of Things (IoT) applications and the increasing dependence of users on wireless connections, indoor location based service(LBS) under 5G-Public-Private Partnership (5G-PPP) using cases have received more attention and get rapid development. Thanks to the safty, security and customization of 5G network pointed by 5G forum white paper, indoor positioning systems using unified 5G New Radio (NR) signals have become the focus of the next generation of visible light positioning (VLP) systems. In 5G New Radio(NR) frame, totally 192 subcarriers are used to carry positioning reference signal(PRS). In order to improve the positi…
Joint Optimization of Sensor Selection and Routing for Distributed Estimation in Wireless Sensor Networks
2014
Avances recientes en redes inalámbricos de sensores (WSNs, Wireless Sensor Networks) han posibilitado que pequeños sensores, baratos y con recursos limitados tanto en sensado, comunicación, como en computación, sean desplegados a gran escala. En consecuencia, las WSNs pueden ofrecer diversos servicios en importantes aplicaciones para la sociedad. Entre las varias restricciones que aparecen en el diseño de WSNs, tales como la limitación en energía disponible, procesamiento y memoria, la limitación en energía es muy importante ya que en muchas aplicaciones (ej., monitorización remota de diferentes entornos, edificios administrativos, monitoreo del hábitat, los incendios forestales, la atenció…
Average Age of Information in Wireless Powered Mobile Edge Computing System
2022
Mobile edge computing (MEC) has been recognized as a promising technique to provide enhanced computation services for low-power wireless devices at the network edge. How to evaluate the timeliness of the task and data delivery is critical for the development of MEC applications. Considering a wireless powered MEC system, in this letter we study the average age of information (AoI), which is a crucial performance metric to measure the freshness of information. Specifically, in the considered system, a sensor node harvests energy from an energy transmitter and transmits computation tasks to the MEC server. The charging time of the sensor node’s capacitor, the waiting time and service time at …
A Self-powered Ambient Light Power Measurement Platform with Time-domain Readout
2021
Internet of Things (IoT) provides more and more adequate infrastructures for many applications and advanced services. This scenario promotes the ability to satisfy the growing demand for innovative measuring systems, increasingly popular consisting of intelligent nodes, totally wireless, easy to install, and that requires the least possible maintenance. In this context, this paper aims to contribute to state of the art with an energy-autonomous and battery-free measurement platform designed to measure the ambient light power when its level exceeds the sensitivity threshold. The measurement platform utilizes a single transducer to scavenge energy and concurrently measure the ambient light in…
Designing Features for Fido: What Makes Animal-Computer Interaction So Different From Human-Computer Interaction?
2013
Lehtonen, Jaana Designing Features for Fido: What Makes Animal-Computer Interaction So Dif-ferent From Human-Computer Interaction? Jyväskylä: University of Jyväskylä, 2013, 21 p. Information Systems Science, Bachelor’s thesis Supervisor: Kuparinen, Liisa Animal-computer interaction aims to allow animals to interact not only with computers but their owners and other humans through computerised interfaces. This thesis studies the existing research on the main characteristics of ani-mal-computer interaction and what sets it apart from human-computer interac-tion. The main focus is on recognising and defining different kinds of chal-lenges affecting the development of tools and systems for anim…
Energy efficient optimisation for large-scale multiple-antenna system with WPT
2018
In this study, an energy-efficient optimisation scheme for a large-scale multiple-antenna system with wireless power transfer (WPT) is presented. In the considered system, the user is charged by a base station with a large number of antennas via downlink WPT and then utilises the received power to carry out uplink data transmission. Novel antenna selection, time allocation and power allocation schemes are presented to optimise the energy efficiency of the overall system. In addition, the authors also consider channel state information cannot be perfectly obtained when designing the resource allocation schemes. The non-linear fractional programming-based algorithm is utilised to address the …
Dynamic MAC Parameters Configuration for Performance Optimization in 802.11e Networks
2006
Quality of service support in wireless LAN is a theme of current interest. Several solutions have been proposed in literature in order to protect time-sensitive traffic from best-effort traffic. According to the EDCA proposal, which is a completely distributed solution, the service differentiation is provided by giving probabilistically higher number of channel accesses to stations involved in real-time applications. To this purpose, the MAC parameter settings of each contending stations can be tuned dynamically. In this paper, we face the problem of tuning the EDCA MAC parameters in common scenarios in which a given number of low-rate delay-sensitive traffic flows share the channel with so…
Remarks on IEEE 802.11 DCF Performance Evaluation, IEEE Communication Letters, Vol. 9, Issue 8, Aug 2005 pp:765 - 767
2005
This letter presents a new approach to evaluate the throughput/delay performance of the 802.11 Distributed Coordination Function (DCF). Our approach relies on elementary conditional probability arguments rather than bidimensional Markov chains (as proposed in previous models), and can be easily extended to account for backoff operation more general than DCF's one
On the accuracy of some common modeling assumptions for EDCA analysis
2005
Several models have been discussed in literature in order to evaluate the performance of the EDCA differentiation mechanisms. Despite of the exponential back off rules, usually the EDCA protocol has been modeled as a persistent slotted access protocol, and summarized into a set of access probabilities. These models often show a very different complexity and accuracy, according to the basis assumptions. In this paper, we propose a new modeling approach for EDCA, in which the medium access is described in terms of backoff counter comparisons, contention by contention, and no restrictive hypothesis is considered. Through our model, we verify the applicability of the most common protocol simpli…