《电子信息专业英语》课件 Lesson 15 Light Fidelity.pptVIP

Lesson15LightFidelityKeywords■light[la?t]光■fidelity[f?del?t?]保真度■lamp[l?mp]灯■visible[?v?z?bl]可见的■ultraviolet[?ltr?va??l?t]紫外的■infrared[?nfr?red]红外线的■radiation[re?d?e??(?)n]辐射■visibility[v?z?b?l?t?]能见度■penetrate[pen?tre?t]穿透■electromagnetic[?,lektr?(?)m?gnet?k]电磁的■interference[?nt?f??r(?)ns]干扰■downside[da?nsa?d]缺点■security[s?kj??r?t?]安全性■fragility[fr?d??l?t?]易碎性■automation[??t?me??(?)n]自动化■layout[le?a?t]布局■hazardous[h?z?d?s]有危险的■geolocation[d???l??ke??n]地理定位■precision[pr?s??(?)n]精度

■工作任务：认识LiFi以及LiFi的使用条件和优势■学习目标：掌握LiFi的基本概念，了解其工作原理■重点难点：LiFi的工作原理和特点■推荐学时：6学时1.WhatisLiFi?LiFi(shortforlightfidelity)isatechnologyforwirelesscommunicationbetweendevicesusinglighttotransmitdataandposition.InitspresentstateonlyLEDlampscanbeusedforthetransmissionofvisiblelight.ThetermwasfirstintroducedbyHaraldHaasduringa2011TEDGlobaltalkinEdinburgh.Intechnicalterms,LiFiisavisiblelightcommunicationssystemthatiscapableoftransmittingdataathighspeedsoverthevisiblelightspectrum,ultravioletandinfraredradiation.Thisopticalwirelesscommunications(OWC)technologyuseslightfromlight-emittingdiodes(LEDs)asamediumtodelivernetworked,mobile,high-speedcommunicationinasimilarmannertoWiFi.Visiblelightcommunications(VLC)worksbyswitchingthecurrenttotheLEDsoffandonataveryhighrate,tooquicktobenoticedbythehumaneye.AlthoughLiFiLEDswouldhavetobekeptontotransmitdata,theycouldbedimmedtobelowhumanvisibilitywhilestillemittingenoughlighttocarrydata.Thelightwavescannotpenetratewallswhichmakesamuchshorterrange,thoughmoresecurefromhacking,relativetoWiFi.2.ThecharacteristicsofLiFiLiFihastheadvantageofbeingusefulinelectromagneticsensitiveareassuchasinaircraftcabins,hospitalsandnuclearpowerplantswithoutcausingelectromagne