Your SlideShare is downloading. ×
FREE SPACE OPTICAL COMMUNICATION
Upcoming SlideShare
Loading in...5
×

Thanks for flagging this SlideShare!

Oops! An error has occurred.

×

Saving this for later?

Get the SlideShare app to save on your phone or tablet. Read anywhere, anytime - even offline.

Text the download link to your phone

Standard text messaging rates apply

FREE SPACE OPTICAL COMMUNICATION

3,674
views

Published on

Published in: Business, Technology

1 Comment
0 Likes
Statistics
Notes
  • Be the first to like this

No Downloads
Views
Total Views
3,674
On Slideshare
0
From Embeds
0
Number of Embeds
1
Actions
Shares
0
Downloads
366
Comments
1
Likes
0
Embeds 0
No embeds

Report content
Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
No notes for slide

Transcript

  • 1. A SEMINAR ON FREE SPACE OPTICAL COMMUNICATION By T venkatesh
  • 2.
    • CONTENTS
      • Introduction
      • History
      • How it works
      • Advantages
      • Challenges
      • System design
      • Transmission security
      • Conclusion
  • 3.
    • Introduction
      • Fibre less laser driven technology
      • No licensing and frequency coordination required
      • Operating wavelength range
    • 1) 780-900 nm
    • 2) 1500-1600nm
      • Provides a line of sight link
      • Fso links are full duplex
      • Easy to install for last mile &campus
  • 4.
    • History of fso
      • Greeks used sun light for messaging
      • In late nineteenth century graham bell demonstrated it.
      • Used for defence
  • 5. Last mile options
      • Definition of last mile
      • Cable
      • Fiber
      • Licenced and unlicenced fixed wireless
  • 6. Last mile solutions
      • Copper based solution
    • 1.Slower copper based solution eg.
    • ISDN,DDS [ 56 kbps,128 kbps ]
    • 2.Higher copper based solution eg.
    • T-1 circuit [24 channel]
    • T-3 circuit [28 t-1]
    • Security is based on the burying
    • the wires in the grounds
    • Intrusion detection system standpoint
    • is used for undectable purpose
  • 7.
      • Wireless connection
    • 1. Distribute data everyone ,security is judged by the wep
    • 2. Licence req. To planning & coordination
    • 3. Susceptible To Rain ,Link Length
    • 4. PP microwave provide higher capacity
    • Eg. LMDS
      • Fiber optic based solution
    • 1.Fiber optics are two type
    • A) Single mode [upto 60km]
  • 8.
    • B)Multi Mode [Upto 2km]
    • 2)Fiber Optics Are
    • Secure
    • Provide speed in terabyte
    • Protected from tapping
    • Imposible to detect light pulse
      • Free space optics
    • 1)No Cables Required
    • 2)Transmitted In Atmosphere
    • 3)Require Line Of Site Availability
  • 9. 4)Units are full duplex 5)No requirement of the license 6)Speed upto tera byte 7)Simplifying Wiring And Cabeling,low Cost 8)No roof space and spectrum license req. 9)Low error rate, high speed
  • 10. HOW IT WORKS
  • 11. LASER PHOTON DETECTOR RECEIVER DIGITAL DATA
  • 12.
    • Advantages
      • Fso laser beam cannot be detected with rf meter or spectrum analyser
      • Los path cannot be intercepted easily
      • Data can be transmitted over an encrypted connection
      • Freedom from licensing and regulation
      • Possble to mount inside the building
  • 13.
    • Challenges
      • Atmosphere
      • Physical obstraction
      • Scientillation
      • Solar interface
  • 14.
      • Atmosphere challenge
    • 1.Fog
    • It affect on near infrared wavelength
    • And have same effect as rainfall have on the
    • rf
      • Physical obstructions
    • 1.These can be removed by widely spaced
    • Redundant transmitters and large receive optics
  • 15.
      • Scintillation
    • These can be removed by automatic gain
    • control char.,Tuned received
    • Filtering,clock recovery phase lock
    • Loop time constant
      • Solar interference
    • It can be combated by
    • 1.Long pass optical filter windo
    • 2.Optical Narrowband Filtering
  • 16.
    • System design
      • Line of sight operation
      • Spectral allocation
      • Fso link equation
      • Alternate routing
      • Network topologies
      • Network scalability
      • Coverage area
      • Deploymaent and installation
  • 17. System performance
      • Bandwidth and system capacity
      • Absorption and scattering losses
      • Rayleigh scattering
      • Aerosol,particles,& cloud scattering
      • Atmospheric scintillation
      • Fog
      • Service provider cost
  • 18.
      • Bandwidth and system capacity
    • 1.Fso use onoff keying for modulation
    • eg. Light pointe giga link system
    • 2.Speed 1gbps-160gbps On Per Link
    • Rayleigh scattering
    • It occur due to dust and moleculer particles that are small than wavelength
    • Of laser transmission
    • Scattering losses decreasing by -.4 with increment in wavelength
  • 19.
      • Scintillation
      • Due to temp.Difference b/w ground and air
    • And the resulting heat exchange
      • Index change according temp.Diff. Heat exchange cause local index variation that affect the laser propagation
      • Fog
    • Solution Of The Fog Is
    • 1.Link planning
    • 2.Multipath
  • 20. Transmission security
    • To prevent the signal interception we use
      • Directional transmission
    • Broader signal path have chance to intercept the beam in fso beam is very
    • Narrow
      • Absense of side lobes
    • Fso have no side lobs.
  • 21. Conclusion FSO networks can be rapidly deployed to provide immediate service to the customers. Some believe that it may be the unlimited bandwidth solution for the metro urban core of downtown building-to-building communication, as well as the optimal technology for home-to-home and office-to-office connectivity. FSO adds the wireless feature to the OFC and thus provides the high bandwidth requirements.
  • 22. Thank You