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1. Communicating with cubic millimeter computer

2. ACKNOWLEDGEMENT
I express thanks to the following individuals who have contributed
in various ways
I would like to thank
 venerated Head of the Department of Telecommunication,
Mr.Natarajan for his valuable guidance and help
 Former Head of Department, Dr. Vijay Kumar B.P. for his
guidance and help
 Mr. Venu K.N. for his encouragement and for recurrently
providing support throughout
 Mrs. Parimala P for her valuable advice in the hour of need.
 I am thankful to the entire staff , for being helpful and
providing the requisite facilities
 Lastly, I am also thankful to my family and friends for their
valuable advice in the hour of need.
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3. What is Smart Dust?
 A tiny dust size device with extra-ordinary
capabilities.
 Each element is known as “mote”
 Often called micro electro-mechanical sensors
 Combines sensing, computing, wireless
communication capabilities and autonomous power
supply within volume of only few millimeters.
 Useful in monitoring real world phenomenon
without disturbing the original process.
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4.  small and light weight
 they can remain suspended in the
environment like an ordinary dust
particle
 small enough to remain suspended in air,
buoyed by air currents in the direction of
flow, sensing and communicating for
hours or days
 very hard to detect the presence of
the Smart Dust
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5. Smart Dust Mote
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6. HISTORY
Conceived by Dr. Kristofer S. J.
Pister of University of California,
Berkeley in 1998
An entire communication system
integrated in a cubic mm of
package
The Defence Advanced Research
Projects Agency (DARPA) was
among the original patrons of the
mote idea
One of the initial mote ideas
implemented for DARPA allows
motes to sense battlefield
conditions
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7. ARCHITECTURE
A single Smart Dust mote has:
MEMS sensors
MEMS beam steering mirrors for optical transmission
MEMS corner cube retro reflector for passive optical transmission
An optical receiver
Signal processing and control circuitry
A power source based on thick film batteries and solar cells
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9. SENSOR
 Sensors may include one or more
motion or environment sensors
 temperature, pressure, vibration,
acceleration, light, magnetic, or
acoustic devices
 more sophisticated sensors also
include the ability to perform
chemical analysis to identify
airborne or liquid substances
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N
S
E
W
2 Axis Magnetic
Sensor
2 Axis
Accelerometer
Light Intensity
Sensor
Humidity Sensor
Pressure Sensor
Temperature
Sensor

10. How Smart dust works?
 Run by microcontroller
• Determines the task performed by the mote
• Controls power
 Most of the time mote is off with only timers running
 When a timer expires, it powers mote to carry out a job , then powers
off.
 Primary constraint of smart dust is volume
--constraint on energy

11. Communicating with a Smart dust
 Radio Frequency Transmission
 Optical transmission technique
(Laser based Communication)
OPTICAL COMMUNICATION
PASSIVE REFLECTIVE SYSTEMS ACTIVE-STEERED LASER SYSTEMS

12. Radio Frequency Transmission
Based on the generation, propagation and detection of
electromagnetic waves with a frequency range from tens of kHz to
hundreds of GHz.
Multiplexing techniques: time, frequency or code-division
multiplexing.
Their use leads to modulation, band pass filtering,
demodulation circuitry, and additional circuitry, all of which
needs to be considered, based on power consumption.

13. Pros
Long range
Line-of-sight path not required
Not severely affected by rain, fog or atmospheric turbulence
Cons
Antenna may be too large for dust motes
Requires modulator, demodulator, filtering (power consumption)
Requires complex multiplexing scheme (TDMA, FDMA, CDMA)

14. Passive reflective Systems
• establish a bi-directional communication link
between dust nodes and a base station transceiver
(BST)
• For downlink communication (BST to dust), the
base station points a modulated laser beam at a
node and uses a simple optical receiver to
decode the incoming message
• For uplink communication (dust to BST), the
base station points an un-modulated laser
beam at a node, which in turn modulates and
reflects back the beam to the BST for which the
dust nodes are equipped with a Corner Cube
Retro Reflector (CCR)

15. Working of a CCR
• CCR comprises three mutually perpendicular mirrors of
gold-coated polysilicon
• The CCR has the property that any incident ray of light is
reflected back to the source (provided that it is incident
within a certain range of angles centered about the cube’s body
diagonal)
• If one of the mirrors is misaligned, this retro-reflection
property is spoiled.
• CCR illuminated by an external light source transmits back a
modulated signal at kilobits per second.
• Since the dust mote itself does not emit light, the passive
transmitter consumes little power. Hence the name.

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The BTS contains a laser whose beam illuminates an area
containing dust motes.
This beam can be modulated with downlink data, including
commands to wake up and query the dust motes.
When the illuminating beam is not modulated, the dust
motes can use their CCRs to transmit uplink data back to the
base station.
A high frame-rate CCD video camera at the BTS sees” these
CCR signals as lights blinking on and off.
It decodes these blinking images to yield the uplink data.

18. Active steered laser systems
It uses an active steered onboard
laser diode based transmitter to send
a collimated laser beam to a station
It consist of a laser diode,
collimating lens and beam steering
mirrors for the communication
With the laser diode and the set of
beam scanning mirrors, we can
transmit data in any direction desired,
allowing the mote to communicate
with other Smart Dust motes.

19. Pros
LLonger range than passive links (up to about 10 km)
Higher bit rates than passive links (up to about 1 Mbps)
With multi-hop, avoids need for every dust mote to have line-of-sight path
to base station
Utilizes space-division multiplexing
Only baseband electronics are required
Cons
 Requires protocol to steer directional transmitters
Requires higher power than passive transmitter
Affected by rain, fog, atmospheric turbulence

20. Cost and availability
 Prices of dust implementation vary on desired mote
capability , installation requirement and volume of
purchase
 Presently two main vendors are there: Crossbow
Technology and Microstrain
 Present cost of individual motes $50 each, dropping
below $1 per mote in the near future
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21. Why smart dust?
Physical attributes:
• Small and lightweight
• Low power consumption
Networking capabilities:
• Networking functions are seamless and automatic
• Multiple networks can be in use simultaneously
Data transmission capabilities:
• On-board data acquisition supports many missions
• Software support for many sensor configurations
• Data can be carried through network to command
centres

22. Disadvantages
 Privacy : mischievous ,unethical ,illegal purposes
 Security: network reprogrammablity
 Standards: no existing standards
 Environmental impacts : not easily or inexpensively
retrieved
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23. Where is smart dust used??
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Environmental
monitoring
Measuring structural integrity
of a building or any other
structure

24. Habitat monitoring:
A biologist could equip an endangered animal with a collar containing a
mote that senses position, temperature, etc.
Military Application :
To detect truck movement in a remote area thousands of motes
are scattered. When an enemy truck drives through the area the
commander can track the path that the truck is following through
the field of motes.
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25. Health And Wellness
Monitoring
Enter human bodies and check for
physiological problems
Virtual keyboards
Virtual keyboards
Glue a dust mote to each
fingertips. Accelerometers will
sense the orientation and
motion of each of the fingertip
and talk to the computer on
your watch
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Health And Wellness Monitoring
Enter human bodies and check for
physiological problems

26. Major Challenges!!
difficult to fit these devices in a small Smart Dust both size wise
and Energy wise.
With devices so small, batteries present a massive addition of
weight.
Privacy and security issues – Though smart dust can be used
as a total surveillance device, abuse of such technology can cost
us our privacy and security.
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27.  There are many ongoing researches on Smart Dust, the main purpose will to
make mote as small as possible and to make it available at a low price.
Soon we will see smart dust being used in varied application from
all spans of life!
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28. Future scope
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29. Thank you
SHIVANI PRASADPRASAD
1MS09TE049
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