Telecom最新文献_第9页

State-of-the-Art Techniques in RF Energy Harvesting Circuits 射频能量收集电路的最新技术

Telecom Pub Date : 2021-10-23 DOI: 10.3390/telecom2040022

Ioannis D. Bougas, Maria S. Papadopoulou, A. Boursianis, Konstantinos-Iraklis D. Kokkinidis, S. Goudos

引用次数: 13

Advanced Resources Reservation in Mobile Cellular Networks: Static vs. Dynamic Approaches under Vehicular Mobility Model 移动蜂窝网络中的高级资源预留:车辆移动模型下的静态与动态方法

Telecom Pub Date : 2021-09-26 DOI: 10.3390/telecom2040020

P. Fazio, M. Tropea

{"title":"Advanced Resources Reservation in Mobile Cellular Networks: Static vs. Dynamic Approaches under Vehicular Mobility Model","authors":"P. Fazio, M. Tropea","doi":"10.3390/telecom2040020","DOIUrl":"https://doi.org/10.3390/telecom2040020","url":null,"abstract":"Many studies in literature have shown that the bandwidth of an ongoing flow can dynamically change during multimedia sessions and an efficient bandwidth allocation scheme must be employed. This paper focuses its attention on the management of predictive services in Wireless Infrastructure Dynamic Networks. In particular, two classes of service are considered: NSIS-Mobility Independent Predictive and NSIS-Mobility Dependent Predictive, where NSIS is the Next Steps in Signaling protocol, employed for resources reservation in Integrated Services architectures. A general prediction technique is proposed, based both on the analysis of time spent into a cell by mobile nodes and on the probabilities of hand-in and hand-out events of mobile nodes from wireless cells. User mobility needs to be firstly analyzed and a novel realistic mobility model has been considered, differently from some existing works in which synthetic mobility is generated. The analysis of user mobility is mandatory when the reduction of passive resource reservations for NSIS-MIP users is desired, with a good enhancement in system utilization. Moreover, predictive reservation and admission control schemes have been integrated. The performance of the 2D wireless system is evaluated in terms of average system utilization, system outage probability, number of admitted flows and reservation prediction errors. We provided to carry out an extensive simulation campaign, in order to assess the goodness of the proposed idea: we verified that good results (in terms of perceived utility, bandwidth and admitted flows) can be obtained, outperforming also some existing works.","PeriodicalId":301561,"journal":{"name":"Telecom","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132903586","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Wearable Flexible Antenna for UWB On-Body and Implant Communications 用于超宽带体上和植入通信的可穿戴柔性天线

Telecom Pub Date : 2021-09-06 DOI: 10.3390/telecom2030019

Mariella Särestöniemi, M. Sonkki, S. Myllymäki, C. Pomalaza-ráez

{"title":"Wearable Flexible Antenna for UWB On-Body and Implant Communications","authors":"Mariella Särestöniemi, M. Sonkki, S. Myllymäki, C. Pomalaza-ráez","doi":"10.3390/telecom2030019","DOIUrl":"https://doi.org/10.3390/telecom2030019","url":null,"abstract":"This paper describes the development and evaluation of an on-body flexible antenna designed for an in-body application, as well as on-body communications at ISM and UWB frequency bands. The evaluation is performed via electromagnetic simulations using the Dassault Simulia CST Studio Suite. A planar tissue layer model, as well as a human voxel model from the human abdominal area, are used to study the antenna characteristics next to human tissues. Power flow analysis is presented to understand the power flow on the body surface as well as within the tissues. Simulation results show that this wearable flexible antenna is suitable for in-body communications in the intestinal area, e.g., for capsule endoscopy, in the industrial, scientific, and medical (ISM) band and at lower ultra-wideband (UWB). At higher frequencies, the antenna is suitable for on-body communications as well as in-body communications with lower propagation depth requirements. Additionally, an antenna prototype has been prepared and the antenna performance is verified with several on-body measurements. The measurement results show a good match with the simulation results. The novelty of the proposed antenna is a compact size and the flexible substrate material, which makes it feasible and practical for several different medical diagnosis and monitoring applications.","PeriodicalId":301561,"journal":{"name":"Telecom","volume":"88 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133132278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 6

High-Efficiency Triple-Band RF-to-DC Rectifier Primary Design for RF Energy-Harvesting Systems 射频能量收集系统的高效三频带射频-直流整流器初级设计

Telecom Pub Date : 2021-08-09 DOI: 10.3390/telecom2030018

Maria S. Papadopoulou, A. Boursianis, C. Volos, I. Stouboulos, S. Nikolaidis, S. Goudos

{"title":"High-Efficiency Triple-Band RF-to-DC Rectifier Primary Design for RF Energy-Harvesting Systems","authors":"Maria S. Papadopoulou, A. Boursianis, C. Volos, I. Stouboulos, S. Nikolaidis, S. Goudos","doi":"10.3390/telecom2030018","DOIUrl":"https://doi.org/10.3390/telecom2030018","url":null,"abstract":"Radio Frequency (RF) energy harvesting has been emerged as a potentially reliable method to replace the costly and difficult to maintain source of low-power wireless sensor networks. A plethora of dual-band rectifier designs has been proposed in the literature operating in various frequency bands. In this paper, a triple-band RF-to-DC rectifier that operates in the frequency bands of LoRaWAN, GSM-900, and WiFi 2.4 GHz is presented. The system is composed of an impedance-matching circuit, an RF-to-DC rectifier, that converts the ambient RF energy into DC voltage able to feed low-power devices, and an output load. The proposed system resonates at three different frequencies of 866 MHz, 948 MHz and 2423 MHz, which fall within the aforementioned frequency bands of interest. The feasible solution of the proposed system was based on a dual-band rectifier operating in the frequency bands of LoRaWAN and GSM-900. A series of shunt stubs was utilized in the initial design to form the feasible solution of the proposed system. The proposed triple-band rectifier was optimized using a powerful optimization algorithm, i.e., the genetic algorithm. The overall system exhibited improved characteristics compared to the initial design in terms of its resonance. Numerical results demonstrated that the overall system exhibited an efficiency of 81% with 3.23 V of the output voltage, for an input power of 0 dBm and a load of 13 kOhm.","PeriodicalId":301561,"journal":{"name":"Telecom","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133299092","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Reinforcement Learning-Enabled UAV Itinerary Planning for Remote Sensing Applications in Smart Farming 基于强化学习的无人机行程规划在智能农业中的遥感应用

Telecom Pub Date : 2021-07-01 DOI: 10.3390/TELECOM2030017

Saeid Pourroostaei Ardakani, A. Cheshmehzangi

{"title":"Reinforcement Learning-Enabled UAV Itinerary Planning for Remote Sensing Applications in Smart Farming","authors":"Saeid Pourroostaei Ardakani, A. Cheshmehzangi","doi":"10.3390/TELECOM2030017","DOIUrl":"https://doi.org/10.3390/TELECOM2030017","url":null,"abstract":"UAV path planning for remote sensing aims to find the best-fitted routes to complete a data collection mission. UAVs plan the routes and move through them to remotely collect environmental data from particular target zones by using sensory devices such as cameras. Route planning may utilize machine learning techniques to autonomously find/select cost-effective and/or best-fitted routes and achieve optimized results including: minimized data collection delay, reduced UAV power consumption, decreased flight traversed distance and maximized number of collected data samples. This paper utilizes a reinforcement learning technique (location and energy-aware Q-learning) to plan UAV routes for remote sensing in smart farms. Through this, the UAV avoids heuristically or blindly moving throughout a farm, but this takes the benefits of environment exploration–exploitation to explore the farm and find the shortest and most cost-effective paths into target locations with interesting data samples to collect. According to the simulation results, utilizing the Q-learning technique increases data collection robustness and reduces UAV resource consumption (e.g., power), traversed paths, and remote sensing latency as compared to two well-known benchmarks, IEMF and TBID, especially if the target locations are dense and crowded in a farm.","PeriodicalId":301561,"journal":{"name":"Telecom","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125029947","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Game-Theoretical Approaches for Service Provisioning in Network Virtualization: Survey, Taxonomies and Open Challenges 网络虚拟化中服务供应的博弈论方法:调查、分类和开放挑战

Telecom Pub Date : 2021-06-30 DOI: 10.3390/telecom2030016

Jihen Bennaceur, H. Ahmadi, Sami Souhi

引用次数: 3

Performance Evaluation of Radio Frequency Interference Measurements from Microwave Links in Dense Urban Cities 密集城市微波链路射频干扰测量性能评价

Telecom Pub Date : 2021-05-19 DOI: 10.22541/AU.162139766.66310309/V1

M. Adelabu, A. Imoize, G. U. Ughegbe

{"title":"Performance Evaluation of Radio Frequency Interference Measurements from Microwave Links in Dense Urban Cities","authors":"M. Adelabu, A. Imoize, G. U. Ughegbe","doi":"10.22541/AU.162139766.66310309/V1","DOIUrl":"https://doi.org/10.22541/AU.162139766.66310309/V1","url":null,"abstract":"Radio frequency interference (RFI) constitutes a significant problem in\u0000achieving a good quality of service in radio links. Several techniques\u0000have been proposed to identify and mitigate RFI in wireless networks.\u0000However, most of these techniques are not generalized for all\u0000propagation environments due to their varying geographical features. The\u0000need for extensive frequency scan measurements on the links to identify\u0000the available channels, evaluate the performances of the links, and\u0000detect RFI in the channels becomes imperative. In this study,\u0000performance evaluation of frequency scan measurements from active\u0000microwave links comprising eighteen base stations is presented. The\u0000measurements equipment comprises a spectrum analyzer and a 0.6-meter\u0000antenna dish. The frequency scans were taken at 6GHz, 7GHz, and 8GHz\u0000with full azimuth coverage of the horizontal and vertical polarization.\u0000Measured data were processed to determine the available frequencies and\u0000RFI in the channels. The histogram and probability density function of\u0000the frequency scans were computed. The cumulative distribution functions\u0000were determined, and the statistical error characteristics of the\u0000frequency scans for the estimated normal distribution and the estimated\u0000fitness curve were derived. The short-time Fourier transform of the\u0000noisy signal was obtained, and the signal without noise was recovered\u0000using the inverse short-time Fourier transform. Analysis of the scanned\u0000signals before and after the noise removal is demonstrated. The denoised\u0000signals compare favorably with related results in the preliminary\u0000literature. Overall, the frequency scans would be highly useful in\u0000evaluating RFI measurements and spectrum planning.","PeriodicalId":301561,"journal":{"name":"Telecom","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124666933","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 8

Designing Smart Electromagnetic Environments for Next-Generation Wireless Communications 设计下一代无线通信的智能电磁环境

Telecom Pub Date : 2021-05-12 DOI: 10.3390/TELECOM2020014

Andrea Massa, A. Benoni, P. Da Rú, S. Goudos, Baozhu Li, G. Oliveri, A. Polo, P. Rocca, M. Salucci

引用次数: 38

A Hybrid User Mobility Prediction Approach for Handover Management in Mobile Networks 一种用于移动网络切换管理的混合用户移动性预测方法

Telecom Pub Date : 2021-05-06 DOI: 10.3390/TELECOM2020013

Nasrin Bahra, S. Pierre

{"title":"A Hybrid User Mobility Prediction Approach for Handover Management in Mobile Networks","authors":"Nasrin Bahra, S. Pierre","doi":"10.3390/TELECOM2020013","DOIUrl":"https://doi.org/10.3390/TELECOM2020013","url":null,"abstract":"Mobile networks are expected to face major problems such as low network capacity, high latency, and limited resources but are expected to provide seamless connectivity in the foreseeable future. It is crucial to deliver an adequate level of performance for network services and to ensure an acceptable quality of services for mobile users. Intelligent mobility management is a promising solution to deal with the aforementioned issues. In this context, modeling user mobility behaviour is of great importance in order to extract valuable information about user behaviours and to meet their demands. In this paper, we propose a hybrid user mobility prediction approach for handover management in mobile networks. First, we extract user mobility patterns using a mobility model based on statistical models and deep learning algorithms. We deploy a vector autoregression (VAR) model and a gated recurrent unit (GRU) to predict the future trajectory of a user. We then reduce the number of unnecessary handover signaling messages and optimize the handover procedure using the obtained prediction results. We deploy mobility data generated from real users to conduct our experiments. The simulation results show that the proposed VAR-GRU mobility model has the lowest prediction error in comparison with existing methods. Moreover, we investigate the handover processing and transmission costs for predictive and non-predictive scenarios. It is shown that the handover-related costs effectively decrease when we obtain a prediction in the network. For vertical handover, processing cost and transmission cost improve, respectively, by 57.14% and 28.01%.","PeriodicalId":301561,"journal":{"name":"Telecom","volume":"99 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127165444","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 10

A Conditional Generative Adversarial Network Based Approach for Network Slicing in Heterogeneous Vehicular Networks 基于条件生成对抗网络的异构车辆网络切片方法

Telecom Pub Date : 2021-03-18 DOI: 10.3390/TELECOM2010009

Farnoush Falahatraftar, S. Pierre, S. Chamberland

引用次数: 2