UltraHighSpeed Wireless AdHoc Networks using FreeSpaceOptics FSO

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Ultra-High-Speed Wireless Ad-Hoc Networks using
Free-Space-Optics (FSO)

• Shiv Kalyanaraman, Murat Yuksel, Partha Dutta
• shivkuma_at_ecse.rpi.edu

shiv rpi
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Motivations Free-Space-Optical (FSO) Ad-Hoc
Networks Mobile or Fixed Multi-Hop
Application Mixed RF/FSO Ad-Hoc Networks
(Military Application)
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Bringing Optical Communications and Ad Hoc
Networking Together
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Current Commercial FSO
Point-to-Point Links in dense metros, competing
with wires and leased lines Issue How to
achieve link reliability/availability despite
weather
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Ad-Hoc/Meshed Optical Wireless Why?

• Positive points
• High-brightness LEDs (HBLEDs) are very low cost
  and highly reliable components
• 35-65 cents a piece, and 2-5 per transreceiver
  package upto 10 years lifetime
• Very low power consumption (100 microwatts for
  10-100 Mbps!)
• Even lower power for 1-10 Mbps
• 4-5 orders of magnitude improvement in energy/bit
  compared to RF
• Directional gt Huge spatial reuse gt multiple
  parallel channels for huge bandwidth increases
  due to spectral efficiency
• More Secure Highly directional small size
  weight gt low probability of interception (LPI)
• Issues
• Need line-of-sight (LOS) and alignment of LOS
  network auto-configuration
• Need to deal with weather temporary obstacles,
  alignment loss

Challenge leverage huge benefits while tackling
problems.
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Optical Wireless Commodity components
LEDs
VCSELs
IrDAs
Lasers
Many FSO components are very low cost and
available for mass production.
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Spatial Re-use 2D FSO Arrays 1-100Gbps Backhaul

• 1cm2 LED/PIN gt 1000 pairs in 1ft x 1ft square
  structure
• 100 Gbps aggregate bandwidth ( 1000 x 100 Mbps)

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Aggregate Capacity in 2-d Arrays Interference vs
Density vs Distance
Interference Error vs. Packaging Density

• Bandwidth-Volume Product

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Auto-Alignment 3D Spherical FSO Structures
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Initial Ad-Hoc FSO Prototypes
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Initial Ad-Hoc FSO Prototypes (contd)
Received Light Intensity from the moving train.
Misaligned
Aligned

• Very dense packaging and high mobility are
  feasible.

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Initial FSO Prototypes
Inside of the sphere is coated w/ mirror
Photo-detector
Integrating ball to increase angle of reception
inside is coated with mirror.
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Audio Transmission on FSO Link using low cost
LEDs and Photo Diodes Two Channel Mixing
a) Two transmitters on different channels
b) Single receiver and circuit for both the
channels
Indoor FSO ad-hoc networks
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Indoor Ad-Hoc FSO Music App (contd)
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Hybrids 3D Auto-Alignment with 2D Arrays
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Auto-configuration Location tracking and
management

• Location tracking (optional integration w/ GPS)
• Use highly granular spherical FSO antennas (e.g.
  hundreds of transceivers) ? can detect angle of
  arrival
• Use time of flight or signal strength ? can
  detect distance
• Unlike RF, no need for triangulation sense of
  direction is available.
• Allows easy integration with Community Wireless
  Networks (CWNs)
• Organic network growth

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Emerging Apps Broadband Sensor Networks Eg
Mobile/Fixed Camera Networks

• More than 10,000 public and private cameras in
  Manhattan, 2.5 million in the UK!
• Subways, airports, battlefields, factory
  floors, highways

• Thousands of un-supervised and moving cameras w/o
  centralized processing or control
• Key Mix of Low Power AND High Speed AND
  Ad-Hoc/Unsupervised

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SUMMARY Ultra-Broadband Wireless puzzle falling
in place

• (1) Infinite Spectrum in Thin Air!
• Key use unlicensed spectrum or larger licensed
  bands
• (2) Multi-hop architecture w/ Base-Station
  Interfaces
• Wireless is fundamentally cheap for shorter
  distances, smaller coverage
• Organic architecture auto-conf, self-management
  (10 years of research in ad-hoc networks),
  community wireless
• IP/geographic routing, fully distributed traffic
  engineering mechanisms
• Technology neutral, extensible, modular 802.11x,
  802.16x, FSO
• (2a) Multi-hop Free-space-optics (FSO) using
  ultra-low-cost components for 100 Gbps
  capabilities
• Key Broadband CWNs ad-hoc FSO complementary to
  ongoing advances in FTTH, DSL/Cable, WiMax, 3G
  rollouts.
• Open Problems in upgrading the network and
  transport layers to leverage raw, but distributed
  bandwidth, and tolerate higher bursty losses
  (weather related)

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Thanks!
Student Heroes Jayasri Akella,
sri_at_networks.ecse.rpi.edu Dr. Murat Yuksel
(post-doc) yuksem_at_ecse.rpi.edu Chang Liu,
c.liu_at_ee.unimelb.edu.au David Partyka,
partyd_at_rpi.edu Sujatha Sridharan Bow-Nan Cheng
chengb_at_rpi.edu (CWN project)
shiv rpi