Presentation is loading. Please wait.

Presentation is loading. Please wait.

Professor Z. GHASSEMLOOY Associate Dean for Research Optical Communications Research Group, School of Computing, Engineering and Information Sciences The.

Similar presentations


Presentation on theme: "Professor Z. GHASSEMLOOY Associate Dean for Research Optical Communications Research Group, School of Computing, Engineering and Information Sciences The."— Presentation transcript:

1 Professor Z. GHASSEMLOOY Associate Dean for Research Optical Communications Research Group, School of Computing, Engineering and Information Sciences The University of Northumbria Newcastle, U.K. Free Space Optical Communications

2 Northumbria University at Newcastle, UK 2

3 Outline  Introduction to FSO  FSO  Applications  Issues  Results  Simulation  Experimental  Final remarks 3

4 Free Space Optical (FSO) Communications

5 800BC - Fire beacons (ancient Greeks and Romans) 150BC - Smoke signals (American Indians) 1791/92 - Semaphore (French) Alexander Graham Bell demonstrated the photophone 1 – 1 st FSO (THE GENESIS) (www.scienceclarified.com) 1960s - Invention of laser and optical fibre 1970s - FSO mainly used in secure military applications 1990s to date - Increased research & commercial use due to successful trials When Did It All Start? 5 1 Alexander Graham Bell, "On the production and reproduction of sound by light," American Journal of Sciences, Series 3, pp , Oct

6 ….. BANDWIDTH when and where required. AND THAT IS ? Over the last 20 years deployment of optical fibre cables in the backbone and metro networks have made huge bandwidth readily available to within one mile of businesses/home in most places. But, HUGE BANDWIDTH IS STILL NOT AVAILABLE TO THE END USERS. The Problem? 6

7 Quick to install; only takes few hours No trenches Requires no right of way No license fee Huge bandwidth similar to fibre No electromagnetic interference Complements other access network technologies Achievable range limited by thick fog to ~500m Over 3 km in clear atmosphere 7 No multipath fading – Intensity modulation and direct detection Secure transmission FSO - Features steering and tracking capabilities Used in the following protocols: Ethernet, Fast Ethernet, Gigabit Ethernet, FDDI, ATM, Optical Carriers (OC)-3, 12, 24, and 48.

8 8 (Source: NTT) Access Network Bottleneck 8

9 9 Cellular Network Bottleneck MU BS Microwave link Backhaul “last mile” Mobile switching node Core network RF PTSN Switching centre Microwave radio links (installed or leased) More than one BS is connected to MSN

10 10 BS A BS C BS B Optical fibre Hub BS Mobile switching node Medium capacity microwave link High capacity microwave link Cellular Network Bottleneck

11 Iran Core “Last mile” “Regional” BACKHAUL BS MSN Hub

12 12 Plaintree Systems Inc.

13 13

14 MRV

15 15 xDSL  Copper based (limited bandwidth)- Phone and data combine  Availability, quality and data rate depend on proximity to service provider’s C.O. Radio link  Spectrum congestion (license needed to reduce interference)  Security worries (Encryption?)  Lower bandwidth than optical bandwidth  At higher frequency where very high data rate are possible, atmospheric attenuation(rain)/absorption(Oxygen gas) limits link to ~1km Cable  Shared network resulting in quality and security issues.  Low data rate during peak times FTTx  Expensive  Right of way required - time consuming  Might contain copper still etc FSO Access Network Technology

16 16 DRIVER CIRCUIT POINT A POINT B SIGNAL PROCESSING PHOTO DETECTOR Link Range L FSO - Basics  Cloud  Rain  Smoke  Gases  Temperature variations  Fog and aerosol The transmission of optical radiation through the atmosphere obeys the Beer-Lamberts’s law: P receive = P transmit * exp(-αL) α : Attenuation coefficient This equation fundamentally ties FSO to the atmospheric weather conditions

17 Optical Components – Light Source Operating Wavelength (nm) Laser typeRemark ~850VCSELCheap, very available, no active cooling, reliable up to ~10Gbps ~1300/~1550Fabry-Perot/DFBLong life, compatible with EDFA, up to 40Gbps ~10,000 Quantum cascade laser (QCL) Expensive, very fast and highly sensitive For indoor applications LEDs are used. 17

18 Optical Components – Detectors Material/Structure Wavelength (nm) Responsivity (A/W) Typical sensitivity Gain Silicon PIN300 – 155Mbps 1 InGaAs PIN1000 – 155Mbps 1 Silicon APD400 – 155Mbps 150 InGaAs APD1000 – Quantum –well and Quatum-dot (QWIP&QWIP) ~10,000 Germanium only detectors are generally not used in FSO because of their high dark current. 18

19 Receiver Sensitivity Vs. Detector Area PIN APD Sensitivity (dBm) Photodiode area (mm ) 2 (155Mbit/s) 19

20 Existing System Specifications  Range: 1-10 km (depend on the data rates)  Power consumption up to 60 W  15 data rate up to 100 mbps and =780nm, short range  25 date rate up to 150 Mbps and = 980nm  60 data rate up to 622 Mbps and = 780nm  40 data rate up to 1.5 Gbps and = 780nm  Transmitted power: 14 – 20 dBm  Receiver: PIN (lower data rate), APD (>150 mbps)  Beam width: 4-8 mRad  Interface: coaxial cable, MM Fibre, SM Fibre  Safety Classifications: Class 1 M (IEC)  Weight: up to 10 kg 20

21 Safety Classifications - Point Source Emitter mW 2.5mW 8.8mW 45mW 10mW 50mW class 1 class 1 class 3A class 3B class 1 class 3A class 3B class 1 class 3A class 3B class 1 class 3A class 3B class visible infra-red Total power in a 5cm Lens (mW) Wavelength (nm) Source:BT indoor √ √ with holography 21

22 Power Spectra of Ambient Light Sources P ave)amb-light >> P ave)signal (Typically 30 dB with no optical filtering) 2 nd window IR 22

23 23 Source: Cost Comparison

24 24

25 25

26 26 FSO – System Requirement  Link specifications / data rate  Response time  Timeliness / latency  Data throughput  Reliability  Availability 

27 27 FSO – System Requirement M. Löschnigg, P. Mandl, E. Leitgeb, 2009

28  RF wireless networks - Broadcast RF networks are not scaleable - RF cannot provide very high data rates - RF is not physically secure - High probability of detection/intercept - Not badly affected by fog and snow, affected by rain  A Hybrid FSO/RF Link - High availability (>99.99%) - Much higher throughput than RF alone - For greatest flexibility need unlicensed RF band Hybrid FSO/RF Wireless Networks

29 LOS - Hybrid Systems Video-conference for Tele-medicine CIMIC-purpose and disaster recovery 29

30 30 In addition to bringing huge bandwidth to businesses /homes FSO also finds applications in : Multi-campus university Hospitals Others:  Inter-satellite communication  Disaster recovery  Fibre communication back-up  Video conferencing  Links in difficult terrains  Temporary links e.g. conferences Cellular communication back-haul FSO challenges… FSO - Applications

31 31 Ring Topology Star Topology FSO - Applications

32 DRIVER CIRCUIT POINT A POINT B SIGNAL PROCESSING PHOTO DETECTOR Major challenges are due to the effects of: CLOUD, RAIN, SMOKE, GASES, TEMPERATURE VARIATIONS FOG & AEROSOL FSO - Challenges To achieve optimal link performance, system design involves tradeoffs of the different parameters rd ECAI – Romania, 3-5 July 2009

33 33 EffectsOptionsRemarks Photon absorption Increase transmit optical power Effect not significant FSO Challenges – Rain & Snow = 0.5 – 3 mm 3 rd ECAI – Romania, 3-5 July 2009 A heavy rainfall of 15 cm/hour causes dB/km loss in optical power Light snow about 3 dB/km power loss Blizzard could cause over 60 dB/km power loss Snow attenuation

34 FSO Challenges - Physical Obstructions Pointing Stability and Swaying Buildings EffectsSolutionsRemarks Loss of signal Multipath induced Distortions Low power due to beam divergence and spreading Short term loss of signal Spatial diversity Mesh architectures: using diverse routes Ring topology: User ’ s n/w become nodes at least one hop away from the ring Fixed tracking (short buildings) Active tracking (tall buildings) May be used for urban areas, campus etc. Low data rate Uses feedback 34 3 rd ECAI – Romania, 3-5 July 2009

35 FSO Challenges – Aerosols Gases & Smoke  Mie scattering  Photon absorption  Rayleigh scattering These contribute to signal loss:  Increase transmit power  Diversity techniques  Effect not severe EffectsSolutionsRemarks 35 3 rd ECAI – Romania, 3-5 July 2009 Absorption coefficient Scattering coefficient

36 36 EffectsOptionsRemarks Mie scattering Photon absorption Increase transmit optical power Hybrid FSO/RF Thick fog limits link range to ~500m Safety requirements limit maximum optical power FSO Challenges - Fog = mm 3 rd ECAI – Romania, 3-5 July 2009 Using Mie scattering to predict fog attenuations m and r are the refractive index and radius of the fog droplets, respectively. Qext is the extinction efficiency and n(r) is the modified gamma size distribution of the fog droplets.

37 37 Fog - Predicted specific attenuation at 10 ºC for moderate continental fog

38 38 Weather condition PrecipitationAmount (mm/hr) VisibilitydB Loss/km Typical Deployment Range (Laser link ~20dB margin) Dense fog0 m 50 m m (H.Willebrand & B.S. Ghuman, 2002.) Very clear23 km 50 km m m Thick fog200 m m Moderate fogSnow500 m m Light fogSnowCloudburst m 1 km m 1493 m Thin fogSnowHeavy rain251.9 km 2 km m 3369 m HazeSnowMedium rain km 4 km m 5566 m Light hazeSnowLight rain km 10 km m 9670 m ClearSnowDrizzle km 20 km m m FSO Challenges - Fog 3 rd ECAI – Romania, 3-5 July 2009

39 39 FSO – Fog Experimental Data City of Nice – Jan –July 2006 City of Graze – Jan - July Ref: E Leitgeb et al 2009

40 40 FSO Attenuation 3 rd ECAI – Romania, 3-5 July 2009

41  Background radiation  LOS requirement  Laser safety  Turbulence (scintillation) FSO Challenges - Others 3 rd ECAI – Romania, 3-5 July 2009

42 EffectsOptionsRemarks Irradiance fluctuation (scintillation) Image dancing Phase fluctuation Beam spreading Polarisation fluctuation Diversity techniques Forward error control control Robust modulation techniques Adaptive optics Coherent detection not used due to Phase fluctuation Significant for long link range (>1km) Turbulence and thick fog do not occur together In IM/DD, it results in deep irradiance fades that could last up to ~1-100 μs FSO Challenges - Turbulence 42

43 Cause: Atmospheric inhomogeneity / random temperature variation along beam path.  changes in refractive index of the channel Depends on:  Altitude/Pressure, Wind speed,  Temperature and relative beam size. The atmosphere behaves like prism of different sizes and refractive indices Phase and irradiance fluctuation Zones of differing density act as lenses, scattering light away from its intended path. Thus, multipath. Result in deep signal fades that lasts for ~1-100 μs FSO Challenges - Turbulence 3 rd ECAI – Romania, 3-5 July 2009 P: Channel pressure, Te: Channel temperature

44 Gamma-GammaAll regimes ModelComments Log NormalSimple; tractable Weak regime only I-KWeak to strong turbulence regime KStrong regime only Rayleigh/Negative Exponential Saturation regime only Irradiance PDF by Andrews et al (2001): I x : due to large scale effects; obeys Gamma distribution I y : due to small scale effects; obeys Gamma distribution Kn(.): modified Bessel function of the 2nd kind of order n σ l 2 : Log irradiance variance (turbulence strength indicator) Based on the modulation process the received irradiance is Irradiance PDF: To mitigate turbulence effect we, employ subcarrier modulation with spatial diversity Turbulence – Channel Models 3 rd ECAI – Romania, 3-5 July 2009

45 Using optimal maximum a posteriori (MAP) symbol-by-symbol detection with equiprobable OOK data: Turbulence Effect on OOK OOK based FSO requires adaptive threshold to perform Optimally rd ECAI – Romania, 3-5 July 2009 The threshold depends on the noise level and turbulence strength 

46 Photo- detector array Atmospheric channel Serial/parallel converter Subcarrier modulator.... Data in d(t)d(t) Summing circuit.... DC bias m(t)m(t) m(t)+b o Optical transmitter Spatial diversity combiner Subcarrier demodulator Parallel/serial converter.... Data out d’(t) irir SIM – System Block Diagram 46 3 rd ECAI – Romania, 3-5 July 2009

47 Subcarrier Intensity Modulation  No need for adaptive threshold  To reduce scintillation effects on SIM  Convolutional coding with hard-decision Viterbi decoding (J. P. KIm et al 1997)  Turbo code with the maximum-likelihood decoding (T. Ohtsuki, 2002)  Low density parity check (for burst-error medium): - Outperform the Turbo-product codes. - LDPC coded SIM in atmospheric turbulence is reported to achieve a coding gain >20 dB compared with similarly coded OOK (I. B. Djordjevic, et al 2007)  SIM with space-time block code with coherent and differential detection (H. Yamamoto, et al 2003)  However, error control coding introduces huge processing delays and efficiency degradation (E. J. Lee et al, 2004) 47 3 rd ECAI – Romania, 3-5 July 2009

48 SIM – Our Contributions Multiple-input-multiple-output (MIMO) (an array of transmitters/ photodetectors) to mitigate scintillation effect in a IM/DD FSO link  overcomes temporary link blockage by birds and misalignment when combined with a wide laser beamwidth, therefore no need for an active tracking  provides independent aperture averaging with multiple separate aperture system, than in a single aperture where the aperture size has to be far greater than the irradiance spatial coherence distance (few centimetres)  Provides gain and bit-error performance  Efficient coherent modulation techniques (BPSK etc.) - bulk of the signal processing is done in RF that suffers less from scintillation  In dense fog, MIMO performance drops, therefore alternative configuration such as hybrid FSO/RF should be considered  Average transmit power increases with the number of subcarriers, thus may suffers from signal clipping  Inter-modulation distortion 3 rd ECAI – Romania, 3-5 July 2009

49 49 Subcarrier Modulation - Transmitter 3 rd ECAI – Romania, 3-5 July 2009

50 SIM - Receiver Photo-current R = Responsivity, I = Average power,  = Modulation index, m(t) = Subcarrier signal 50 3 rd ECAI – Romania, 3-5 July 2009

51 51  Performs optimally without adaptive threshold as in OOK  Use of efficient coherent modulation techniques (PSK, QAM etc.) - bulk of the signal processing is done in RF where matured devices like stable, low phase noise oscillators and selective filters are readily available.  System capacity/throughput can be increased  Outperforms OOK in atmospheric turbulence  Eliminates the use of equalisers in dispersive channels  Similar schemes already in use on existing networks  The average transmit power increases as the number of subcarrier increases or suffers from signal clipping.  Intermodulation distortion due to multiple subcarrier impairs its performance But.. Subcarrier Modulation 3 rd ECAI – Romania, 3-5 July 2009

52 SIM - Spatial Diversity  Single-input-multiple-output  Multiple-input-multiple-output (MIMO) 52 3 rd ECAI – Romania, 3-5 July 2009

53 Selection Combining (SELC). No need for phase information Maximum Ratio Combining (MRC) [Complex but optimum] Equal Gain Combining (EGC) Diversity Combining Techniques a i is the scaling factor SIM - Spatial Diversity Assuming identical PIN photodetector on each links, the photocurrent on each link is: 53 3 rd ECAI – Romania, 3-5 July 2009

54 SIM Spatial Diversity – Assumptions Made  The spacing between detectors > the transverse correlation size ρ o of the laser radiation, because ρ o = a few cm in atmospheric turbulence  The beamwidth at the receiver end is sufficiently broad to cover the entire field of view of all N detectors.  Scintillation being a random phenomenon that changes with time makes the received signal intensity time variant with coherence time  o of the order of milliseconds.  With the symbol duration T <<  o the received irradiance is time invariant over one symbol duration rd ECAI – Romania, 3-5 July 2009

55 Eric Korevaar et. al A typical reduction in intensity fluctuation with spatial diversity One detector Two detectors Three detectors Subcarrier Modulation - Spatial Diversity 3 rd ECAI – Romania, 3-5 July 2009

56  Free Space Optics  Characteristics  Challenges  Turbulence - Subcarrier intensity multiplexing - Diversity schemes  Results and discussions  Final remarks 3 rd ECAI – Romania, 3-5 July 2009

57 Normalised SNR at BER of against the number of subcarriers for various turbulence levels for BPSK Increasing the number of subcarrier/users, results In increased SNR SNR gain compared with OOK Error Performance – No Spatial Diversity 3 rd ECAI – Romania, 3-5 July 2009

58 58 BPSK based subcarrier modulation is the most power efficient BPSK BER against SNR for M-ary-PSK for log intensity variance = Error Performance – No Spatial Diversity 3 rd ECAI – Romania, 3-5 July 2009

59 Spatial Diversity Gain Spatial diversity gain with EGC against Turbulence regime 3 rd ECAI – Romania, 3-5 July 2009

60 Spatial Diversity Gain for EGC and SeLC BER = = Zeros of the n th order Hermite polynomial = Weight factor of the nth order Hermite polynomial Dominated by received irradiance, reduced by factor N on each link. Link margin for SelC is lower than EGC by ~1 to ~6 dB 3 rd ECAI – Romania, 3-5 July 2009

61 Most diversity gain region The optimal but complex MRC diversity is marginally superior to the practical EGC Spatial Diversity Gain for EGC and MRC BER = rd ECAI – Romania, 3-5 July 2009

62 62 Delay ≥ Channel coherence time This process is reversed at the receiver side to recover the data Retransmission on different subcarriers Other possibilities: different wavelengths different polarisations Temporal Diversity

63 No TDD1-TDD2-TDD3-TDD5-TDD I o (dBm) (no fading: ) Fading penalty (dB) Diversity gain (dB) (gain / path) 0 (0) 2 (2) 2.68 (1.34) 2.96 (0.99) 3.13 (0.63) Single delay path is the optimum BER =10 -9 Temporal Diversity Gain

64 Multiple-Input-Multiple-Output By linearly combining the photocurrents using MRC, the individual SNRe on each link 64 3 rd ECAI – Romania, 3-5 July 2009

65 MIMO Performance log intensity variance= At BER of :  2 x 2-MIMO requires additional ~0.5 dB of SNR compared with 4- photodetector single transmitter- multiple photodetector system.  4 x 4-MIMO requires ~3 dB and ~0.8 dB lower SNR compared with single transmitter with 4 and 8- photodetectors, respectively rd ECAI – Romania, 3-5 July 2009

66 FSO – Turbulence Chamber Laser Module (Direct Modulation) Power = 3mW λ = 785nm OOK & BPSK Modulator + Demodulator PIN Detector + Amplifier Reflecting mirror Heaters + Fans Turbulence chamber BPSK modulator Carrier 1.5 MHz Data rateA few kHz Turbulence chamber Dimension140 x 30 x 30 cm Temp. range 24 o C – 60 o C Thermometers, T4 Reflecting mirror Optical power meter head 3 rd ECAI – Romania, 3-5 July 2009

67 2.93 V Total fluctuation variance = (V 2 ) Weak scintillation obeys Lognormal distribution (variance < 1) Simulated turbulence is very weak. Signal Distribution Received mean signal + Noise + Scintillation Lognormal fit Observations FSO – With Scintillation Effect 3 rd ECAI – Romania, 3-5 July 2009 Gaussian fit

68 Observation: The optimum symbol decision position in OOK depends on scintillation level Transmitted Received Signal Received No scintillation With scintillation Received Signal ≈ 400mV p-p FSO – OOK With Scintillation Effect 3 rd ECAI – Romania, 3-5 July 2009 Threshold position. ith Threshold range

69 With scintillation No scintillation Demodulated No low Pass filtering Before demodulation Received Signal Demodulated Signal ≈ 400mV p-p Observation: Scintillation does not affect the symbol decision position in BPSK - SIM FSO – BPSK-SIM With Scintillation Effect 3 rd ECAI – Romania, 3-5 July 2009

70 Specifications: 4x4 Du-plex communication link (The FlightStrata 155E) 650 nm wavelength Si APD Data rate: 155 Mbps Maximum length: 3.5 km Automatic Power Control and Auto Tracking Optical nm Agilent Photonic Research Lab FSO Network – Linking Two Universities in Newcastle 3 rd ECAI – Romania, 3-5 July 2009

71 Collaborators Graz Technical University, Austria Houston University, USA UCL Hong-Kong Polytechnic University Tarbiat Modares University, Iran Newcastle University Ankara University, Turkey Agilent Cable Free Technological University of Malaysia Others 3 rd ECAI – Romania, 3-5 July 2009

72 72 Summary AAccess bottleneck has been discussed FFSO introduced as a complementary technology AAtmospheric challenges of FSO highlighted SSubcarrier intensity modulated FSO (with and without spatial diversity) discussed  Wavelet ANN based receivers 3 rd ECAI – Romania, 3-5 July 2009

73 73 Acknowledgements  To many colleagues (national and international) and in particular to all my MSc and PhD students (past and present) and post-doctoral research fellows

74 Iran LS Series Specifications ModelWBLS10WBLS100WBLS100U Ultra-Wide Data Rate10Mbps Full Duplex Distance (meters)up to 800mup to 500mcustom Network ProtocolEthernetFast Ethernet Network Interface10Base-T (RJ45) x1100Base-Tx (RJ45) x1 TransmitterIR - LED Class 1 Wavelength nm Beam width17mrad custom PowerPOE or 48V DC HousingWeatherproof Operating Temp.-40° C to 70° C Relative Humidity5% to 95% Dimensions9” x 6.0” x 12” Weight3.2Kg, 7.5lbs Mounting OptionsWall/Tower, Roof, Non-penetrating

75 Iran ModelWBLS T1/E1WBLS 4T1/4E1 Data Rate4 x 1.54 Mbps or 4 x Mbps 1 x 1.54 Mbps or 1 x Mbps Distance (meters)Up to 800mup to 1600m Network ProtocolATM Network Interface4 x RJ48C1 x RJ48C TransmitterIR - LED Class 1 Wavelength nm Beam width17mrad Power48V DC HousingWeatherproof Operating Temp.-40° C to 70° C Relative Humidity5% to 95% Dimensions9” x 6.0” x 12” Weight3.2Kg, 7.5lbs Mounting OptionsWall/Tower, Roof, Non-penetrating

76 Iran /500 Series Specifications ModelWB410WB4100WB4155WB510 Data Rate10Mbps Full Duplex100Mbps Full Duplex155Mbps Full Duplex10Mbps Full Duplex Distance (meters)1500m750m 2000m Network ProtocolEthernetFast EthernetClear ChannelEthernet Network Interface10Base-T (RJ45) x1100Base-Tx (RJ45) x1SPF- LC Fiber Connect10Base-T (RJ45) x1 TransmitterIR - LED Class 1 Wavelength nm Beam width17mrad custom17mrad PowerPOE or 48V DC 48V DCPOE or 48V DC HousingWeatherproof Operating Temp.-40° C to 70° C Relative Humidity5% to 95% Dimensions15.8" x15.3" x 19" Weight9.0Kg, 20lbs Mounting OptionsWall/Tower, Roof, Non-penetrating

77 Iran ModelWB5100WB5155WB5 T1/E1WB5 T4/E4 Data Rate100Mbps Full Duplex155Mbps Full Duplex1 x 1.54 Mbps or 1 x Mbps 4 x 1.54 Mbps or 4 x Mbps Distance (meters)1000m 3500m2000m Network ProtocolFast EthernetClear ChannelATM Network Interface100Base-Tx (RJ45) x1SPF- LC Fiber Connect1 x RJ48C4 x RJ48C TransmitterIR - LED Class 1 Wavelength nm Beam width17mrad PowerPOE or 48V DC48V DC HousingWeatherproof Operating Temp.-40° C to 70° C Relative Humidity5% to 95% Dimensions15.8" x15.3" x 19" Weight9.0Kg, 20lbs Mounting OptionsWall/Tower, Roof, Non-penetrating

78 Iran XT Series Specifications ModelWBXT10WBXT100WBXT155 Data Rate10Mbps Full Duplex100Mbps Full Duplex155Mbps Full Duplex Distance (meters)3000m2000m Network ProtocolEthernetFast EthernetClear Channel Network Interface10Base-T (RJ45) x1100Base-Tx (RJ45) x1SPF- LC Fiber Connect TransmitterIR - LED Class 1 Wavelength nm Beam width17mrad custom PowerPOE or 48V DC 48V DC HousingWeatherproof Operating Temp.-40° C to 70° C Relative Humidity5% to 95% Dimensions19" x 11" x 32" Weight15Kg, 30lbs Mounting OptionsWall/Tower, Roof, Non-penetrating

79 Iran ModelWBXT T1/E1WBXT T4/E4 Data Rate1 x 1.54 Mbps or 1 x Mbps 4 x 1.54 Mbps or 4 x Mbps Distance (meters)4000m3000m Network ProtocolATM Network Interface1 x RJ48C4 x RJ48C TransmitterIR - LED Class 1 Wavelength nm Beam width17mrad Power48V DC HousingWeatherproof Operating Temp.-40° C to 70° C Relative Humidity5% to 95% Dimensions19" x 11" x 32" Weight15Kg, 30lbs Mounting OptionsWall/Tower, Roof, Non-penetrating


Download ppt "Professor Z. GHASSEMLOOY Associate Dean for Research Optical Communications Research Group, School of Computing, Engineering and Information Sciences The."

Similar presentations


Ads by Google