Search results for "Free-space optical communication"

showing 10 items of 19 documents

Recovery Capabilities of Rateless Codes on Simulated Turbulent Terrestrial Free Space Optics Channel Model

2013

Free Space Optics (FSO) links are affected by several impairments: optical turbulence, scattering, absorption, and pointing. In particular, atmospheric optical turbulence generates optical power fluctuations at the receiver that can degrade communications with fading events, especially in high data rate links. Innovative solutions require an improvement of FSO link performances, together with testing models and appropriate channel codes. In this paper, we describe a high-resolution time-correlated channel model able to predict random temporal fluctuations of optical signal irradiance caused by optical turbulence. Concerning the same channel, we also report simulation results on the error mi…

EngineeringArticle SubjectIrradianceOptical powerSettore ING-INF/01 - ElettronicaSignaloptical turbulenceElectronic engineeringFadingElectrical and Electronic Engineeringtime-serieComputer Science::Information TheorySettore ING-INF/03 - TelecomunicazioniTurbulenceScatteringbusiness.industryRateless codesSettore ING-INF/02 - Campi Elettromagneticilcsh:HE9713-9715Free Space Opticlcsh:Cellular telephone services industry. Wireless telephone industrylcsh:Electrical engineering. Electronics. Nuclear engineeringbusinesslcsh:TK1-9971Communication channelFree-space optical communicationInternational Journal of Antennas and Propagation
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Packet loss recovery in an indoor Free Space Optics link using rateless codes

2014

Free Space Optics (FSO) systems present some important advantages if compared to Radio Frequency links, but they can be affected by several impairments that degrade the link quality and availability. In particular, due to temporary interruptions of the line-of-sight condition between the transmitter and the receiver, packet loss can occur during data transmission. In this work, we present an indoor Free Space Optics link, in which we have systematically generated interruptions of the beam. We demonstrate how the application of the most recent rateless codes, i.e., RaptorQ codes, can strongly improve the link quality by reducing packet loss. In particular, results show that the Packet Error …

EngineeringSettore ING-INF/03 - TelecomunicazioniNetwork packetbusiness.industryTransmitterFree Space Optics (FSO) packet loss rateless codes RaptorQSettore ING-INF/01 - ElettronicaPacket lossEncoding (memory)Electronic engineeringBit error ratebusinessDecoding methodsFree-space optical communicationData transmission2014 16th International Conference on Transparent Optical Networks (ICTON)
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<title>Safety problems in free space optical transmission</title>

2006

The paper is focused on safety of exploitation of optical transmission devices in free space. The subjects concerning propagation of "open" optical stream and its' possible dangerous influence on environment, mainly living organisms are discussed. An attempt to evaluate an installation and exploitation of transmitting devices was made, concerning dangers, requirements, recommendations and restrictions, concluding from accepted safety standards (IEC 60825- 1 :2005, EN 60825-1 :2005 and in Poland PN-EN 60825-1 :2005 "Safety of laser devices - Equipment classification, requirements and user's guide"; IEC 60825-12:2004, EN 60825-12:2005 and in Poland PN-EN 60825-12:2005 "Safety of free space op…

EngineeringTransmission (telecommunications)Laser safetybusiness.industryFree spaceSafety standardsbusinessTelecommunicationsData transmissionFree-space optical communicationSPIE Proceedings
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Ethernet FSO Communications Link Performance Study Under a Controlled Fog Environment

2012

In this letter the performance of a free space optical (FSO) communication link in the presence of fog is experimentally investigated in an indoor environment. A dedicated indoor atmospheric chamber, replicating the outdoor environment, is being used to evaluate the FSO link performance under the fog condition. Theoretical analysis supported by the experimental evaluation has been carried out for the intensity modulation/direct detection on-off keying non-return-to-zero (OOK-NRZ), OOK return-to-zero (OOK-RZ) and four pulse position modulation (4-PPM) modulation formats at the Ethernet baseline data-rate. The results shown indicate that the 4-PPM signalling scheme is the most robust to the f…

Ethernetbusiness.industryOptical linkKeyingXarxes locals sense fil Wi-FiAmplitude-shift keyingComputer Science ApplicationsTelecomunicacióModeling and SimulationPulse-position modulationElectronic engineeringBit error rateEnvironmental scienceElectrical and Electronic EngineeringTelecommunicationsbusinessIntensity modulationComunicació i tecnologiaFree-space optical communication
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Combined effect of turbulence and aerosol on free-space optical links

2017

[EN] Despite the benefits of free-space optical (FSO) communications, their full utilization is limited by the influence of atmospheric weather conditions, such as fog, turbulence, smoke, snow, etc. In urban environments, additional environmental factors such as smog and dust particles due to air pollution caused by industry and motor vehicles may affect FSO link performance, which has not been investigated in detail yet. Both smog and dust particles cause absorption and scattering of the propagating optical signal, thus resulting in high attenuation. This work investigates the joint impact of atmospheric turbulence and dust particle-imposed scattering on FSO link performance as part of the…

Free-space optical communicationMaterials Science (miscellaneous)Airflow02 engineering and technologyAtmospheric sciences01 natural sciencesIndustrial and Manufacturing Engineering010309 opticsOptics0103 physical sciencesTEORIA DE LA SEÑAL Y COMUNICACIONES0202 electrical engineering electronic engineering information engineeringBusiness and International ManagementAbsorption (electromagnetic radiation)AerosolComunicació i tecnologiaPhysicsAerosolsbusiness.industryTurbulenceAttenuationFree-space opticsAtmospheric turbulence020206 networking & telecommunicationsÒpticaAerosolTurbulenceWavelengthExtinction (optical mineralogy)businessFree-space optical communication
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Joint Distribution of Polarization-Multiplexed UWB and WiMAX Radio in PON

2009

[EN] In this paper, the feasibility of the joint distribution of ultra-wideband (UWB) and WIMAX wireless using polarization multiplexing as a coexistence technique is proposed and experimentally demonstrated within the framework of passive optical networks (PON). Four single- and orthogonal-polarization multiplexing schemes are studied targeting to reduce the mutual interference when UWB and WiMAX are distributed jointly through standard single-mode fiber (SSMF) without transmission impairments compensation techniques and amplification. Experimental results indicate successful transmission up to 25 km, in SSMF exceeding the range in typical PON deployments. The radio link penalty introduced…

Integrated optical-wireless accessEngineeringH600WiMAX radioUltra-widebandRadio-over-fiber02 engineering and technologyPolarization-division multiplexingPassive optical networkMultiplexingTelecomunicacióOptical fiber communication020210 optoelectronics & photonicsRadio over fiberTEORIA DE LA SEÑAL Y COMUNICACIONES0202 electrical engineering electronic engineering information engineeringElectronic engineeringComunicació i tecnologiaUltra-wideband radiobusiness.industryPolarization division multiplexing020206 networking & telecommunicationsWiMAXAtomic and Molecular Physics and OpticsbusinessData transmissionFree-space optical communication
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Measured and predicted light attenuation in dense coastal upslope fog at 650, 850, and <inline-formula><math display="inline" overflow="scro…

2008

Free-space optics FSO has gained considerable importance in this decade of demand for high-bandwidth transmission capabilities. FSO can provide the last mile solution, but the availability and reliability issues concerned with it have received increasing attention and need thorough investigation. In this work, we present our results on fog attenu- ation measurement and prediction at wavelengths 650, 850, and 950 nm with peak values up to 500 dB/km. For the attenuation measurement, optical wavelengths are transmitted over the same path of fog in free air to a receiver, measuring the power at every wavelength. The measure- ment of fog attenuation was performed at the France Telecom RD free-sp…

Optical testingbusiness.industryAttenuationGeneral EngineeringAtmospheric modelLight attenuationAtomic and Molecular Physics and OpticsWavelengthOpticsAtmospheric propagationTransmission (telecommunications)Environmental sciencebusinessFree-space optical communicationOptical Engineering
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Rateless codes mitigation technique in a turbulent indoor Free Space Optics link

2014

Free Space Optics (FSO) links are affected by several impairments and, among them, optical turbulence is the most important factor that can degrade the link quality. Due to the presence of this phenomenon, the signal irradiance detected by the receiver fluctuates, thus causing erasure errors and fading events. In this work, we present an indoor Free Space Optics link, in which several turbulence conditions are generated by using two heating elements. We show that the generated turbulence causes erasure errors and packet losses during the data transmission, and we also compare the statistical distribution of the samples with the theoretical models. Moreover, we demonstrate how the applicatio…

PhysicsNetwork packetSettore ING-INF/03 - TelecomunicazioniEncoding (memory)Electronic engineeringBit error rateErasureFadingSettore ING-INF/01 - ElettronicaDecoding methodsFree Space Optics (FSO) optical turbulence rateless codes RaptorQFree-space optical communicationData transmission
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Optical turbulence measurements and channel modeling of an indoor Free Space Optics link

2014

PhysicsOpticsbusiness.industryElectronic engineeringOptical turbulenceLink (geometry)businessFree-space optical communicationCommunication channel2014 Fotonica AEIT Italian Conference on Photonics Technologies
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Model Analysis of Hydrometeor Scattering Effects on Free Space Near-Infrared Links

2012

A promising technology for peer-to-peer connections and urban area networks is represented by wireless communications through free space using optical carrier (Free Space Optics, FSO). This technology ensures high data rates, with relatively low error rates, low power consumption and inherent security. Nevertheless FSO links are quite sensitive to atmospheric condition. Fog droplets, but also raindrops and snowflakes, may introduce severe path attenuation which drastically reduces the channel availability. A parametric model to simulate droplets scattering effects over the FSO link in terms of extinction coefficient, albedo factor and asymmetry coefficient as function of the particle water …

PhysicsScatteringbusiness.industrySettore ING-INF/03 - TelecomunicazioniAttenuationOptical communicationSettore ING-INF/02 - Campi ElettromagneticiMolar absorptivityOpticsfree space optics; water contents; atmospheric data and optical modellingfree space optics atmospheric data and optical modelling water contents.atmospheric data and optical modellingOptical Carrier transmission ratesParametric modelwater contentsfree space opticsSnowflakebusinessFree-space optical communication
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