1 / 45

Fiber Optics For Broadcast Video Applications Eric Fankhauser V.P. Advanced Product Development

Fiber Optics. Need for Fiber Optics technology is constantly increasingDriven by increasing data ratesDeclining implementation costMany advantagesExtremely High Data Carrying CapacityLow signal attenuationFree From Electromagnetic InterferenceLightweight. Presentation Overview. Technologies

jody
Download Presentation

Fiber Optics For Broadcast Video Applications Eric Fankhauser V.P. Advanced Product Development

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


    1. Fiber Optics For Broadcast Video Applications Eric Fankhauser V.P. Advanced Product Development

    2. Fiber Optics Need for Fiber Optics technology is constantly increasing Driven by increasing data rates Declining implementation cost Many advantages Extremely High Data Carrying Capacity Low signal attenuation Free From Electromagnetic Interference Lightweight

    3. Presentation Overview Technologies / Building blocks available Lasers Receivers Fiber Multiplexing Switching System Design Considerations Application Examples

    4. Technologies Available Transmitters (Light Sources) LED’s - 850/1310nm Used with MMF up to 250Mb/s Short distances <1 Km Semiconductor Lasers – 850/1310/1550nm VCSEL’s, Fabry Perot and DFB 1310/1550 can be used with MMF or SMF Short to long distances Low to High data rates (Mb/s to Gb/s)

    5. FP and DFB Laser Spectrum FP laser Emits multiple evenly spaced wavelengths Spectral width = 4nm DFB laser Tuned cavity to limit output to single oscillation / wavelength Spectral width = 0.1nm

    6. Which Laser Type is Better? Fabry Perot Ideal for low cost pt-pt MMF or SMF Not suitable for WDM due to +/- 30nm ? variation Dispersion is a serious issue at Gb/s rates Distributed Feed Back Used in wavelength division multiplexing systems Less susceptible to dispersion than FP laser Used for medium and long haul applications

    7. Technologies Available Receivers (Detectors) PIN Photodiodes Silicon for shorter ?’s (eg 850nm) InGaAs for longer ?’s (eg 1310/1550nm) Good optical sensitivity Avalanche Photodiodes (APD’s) Up to 50% more sensitivity than PIN diodes Primarily for extended distances in Gb/s rates Much higher cost than PIN diodes

    8. Multi-Mode 50/62.5um core, 125um clad Atten-MHz/km: 200 MHz/km Atten-dB/km: 3dB @ 850nm MMF has an orange jacket Single-Mode 9um core, 125um cladding Atten-dB/km: 0.4/0.3dB 1310nm/1550nm SMF has a yellow jacket Fiber Types

    9. Degradation In Fiber Optic Cable Attenuation Loss of light power as the signal travels through optical cable Dispersion Spreading of signal pulses as they travel through optical cable

    10. Attenuation Vs. Wavelength

    11. Light Propagation Light propagates due to total internal reflection Light > critical angle will be confined to the core Light < critical angle will be lost in the cladding

    12. Bending Loss Bends introduce an interruption in the path of light causing some of the optical power to leak into the cladding where it is lost Always keep a minimum bending radius of 5cm on all corners When bundling fibers with tie wraps keep them loose to avoid introducing micro bending into the fiber

    13. Dispersion - Single-Mode FP and DFB lasers have finite spectral widths and transmit multiple wavelengths Different wavelengths travel at different speeds over fiber A pulse of light spreads as it travels through an optical fiber eventually overlapping the neighboring pulse Narrower sources (e.g DFB vs. FP) yield less dispersion Issue at high rates (>1Ghz) for longer distances (>50Km)

    14. Dispersion - Multi-Mode Fiber Modal Dispersion The larger the core of the fiber, the more rays can propagate making the dispersion more noticeable Dispersion determines the distance a signal can travel on a multi mode fiber

    15. Advances in Fiber Optic cable SMF Reduction in the water peak Reduction in loss per Km Corning “SMF28e” Lucent “AllWave” MMF Higher bandwidths Most manu’s going to 50um, graded index fiber

    16. Optimizing Fiber Usage Multiplexing TDM – Time Division Multiplexing WDM – Wave Division Multiplexing

    17. Multiplexing - TDM Done in the electrical domain Can TDM Video+Audio+Data OR Many Video’s, Audio’s, Data’s Increases efficiency of each wavelength Max # of signals based on max link rate

    18. Multiplexing - TDM Latest developments in TDM No synchronization required between signals – All signals 100% independent Low latency (<10us) Small form factor (4/8 Ch in 1/2, 3RU card slot) 8 Ch SDI TDM mux 128 SDI per fiber (CWDM), 320 SDI per fiber (DWDM) 2 Ch HDSDI TDM mux 32 HD per fiber (CWDM), 80 HD per fiber (DWDM) 256 AES per fiber (CWDM), 640 AES (DWDM) RGBHV over 1 fiber/1 wavelength vs 3 fibers

    19. Wavelengths travel independently Data rate and signal format on each wavelength is completely independent Designed for SMF fiber Multiplexing - WDM

    20. Multiplexing - WDM WDM – Wave Division Multiplexing Earliest technology Mux/Demux of two optical wavelengths (1310nm/1550nm) Wide wavelength spacing means Low cost, uncooled lasers can be used Low cost, filters can be used Limited usefulness due to low mux count

    21. Multiplexing - DWDM DWDM – Dense Wave Division Multiplexing Mux/Demux of narrowly spaced wavelengths 400 / 200 / 100 / 50 GHz Channel spacing 3.2 / 1.6 / 0.8 / 0.4 nm wavelength spacing Up to 160 wavelengths per fiber Narrow spacing = higher cost implementation More expensive lasers and filters to separate ?’s Primarily for Telco backbone – Distance Means to add uncompressed Video signals to existing fiber

    22. Multiplexing - CWDM CWDM – Coarse Wave Division Multiplexing Newest technology (ITU Std G.694.2) Based on DWDM but simpler and more robust Wider wavelength spacing (20 nm) Up to 18 wavelengths per fiber Uses un-cooled lasers and simpler filters Significant system cost savings over DWDM DWDM can be used with CWDM to increase channel count or link budget

    23. CWDM Optical Spectrum 20nm spaced wavelengths

    24. DWDM vs. CWDM Spectrum

    25. Optical Routing - Definitions Optical Routers – Optical IN , Optical OUT Photonic Routers – Optical IN & OUT but 100% photonic path OOO- Optical to Optical to Optical switching Optical switch fabric OEO- Optical to Electrical to Optical conversion Electrical switch fabric Regenerative input and outputs

    26. Photonic Technologies MEMS (Micro Electro-Mechanical System) Liquid Crystal MASS (Micro-Actuation and Sensing System )

    27. MEMS Technology Steer the Mirror Tilted mirrors shunt light in various directions 2D MEMS Mirrors arrayed on a single level, or plane Off or On state: Either deployed (on), not deployed (off) 3D MEMS Mirrors arrayed on two or more planes, allowing light to be shaped in a broader range of ways Fast switching speed (ns) Photonic switch is 1:1 IN to OUT (i.e. no broadcast mode)

    28. Liquid Crystal Technology Gate the light No Moving Parts Slow switch speed Small sizes (32x32) Operation based on polarization: One polarization component reflects off surfaces Second polarization component transmits through surface

    29. MASS Technology Steer the fiber Opto-mechanics uses piezoelectric actuators Same technology as Hard Disk Readers and Ink Jet Printer Heads Small-scale opt mechanics: no sliding parts Longer switch time (<10msec)

    30. OEO Technology

    31. OEO Routing Optical <> Electrical conversion at inputs/outputs Provides optical gain (e.g. 23 dB) High BW, rate agnostic electrical switching at core SD, HD, Analog Video (digitized), RGBHV, DVI Fast switching (<10us) Full broadcast mode One IN to ANY/Many outputs Build-in EO / OE to interface with coax plant Save converter costs

    32. Regeneration - Optical vs Photonic Photonic is a lossy device that provide no re-amplification or regeneration Signal coming in at –23dBm leaves at –25dBm OEO router provides 2R or 3R (re-amplify, reclock, regenerate) Signals come in at any level to –25dBm Leave at –7dBm (1310nm) or 0dBm (CWDM)

    33. Applications - Design Considerations Types of signals Signal associations Fiber infrastructure Distance/Loss Redundancy Remote Monitoring

    34. Types of Signals

    35. Design Considerations Signal associations Video, audio, data Together or separate - Issues Fiber infrastructure MMFor SMF Many fibers or one fiber Single clean run for your use (e.g. put in for you) Leased fiber (multiple patches, fusion splices) Distance/Loss Total path loss = (fiber+connectors+passives) Distance can be deceiving - patches, connections, fusion splices

    36. Design Considerations Fault Protection Protection against fiber breaks Important in CWDM and DWDM systems Need 2:1 Auto-changeover function with “switching intelligence” Measurement of optical power levels on fiber Ability to set optical thresholds Revert functions to control restoration

    37. Remote monitoring is key due to distance issues Monitor Input signal presence and validity Laser functionality and bias Optical Link status and link errors Pre-emptive Monitoring Input cable equalization level CRC errors on coax or fiber interface Optical power monitoring Data logging of all error’d events Error tracking and acknowledgment Design Considerations

    38. Diagnostics Interface

    39. Design Examples – Single Link

    40. Post House Facility link - Legacy

    41. Post House Facility Link – New

    42. Fiber STL

    43. RF Over fiber optics -Applications

    44. Large Video MAN – Fully protected

    45. Summary Fiber is an ideal transport medium No magic involved in using fiber optics Many solution options available Proper upfront system design upfront prevents many headaches

    46. Questions Eric Fankhauser ericf@evertz.com www.evertz.com

More Related