Electronics Spectra - SMS Lucknow
Electronics Spectra - SMS Lucknow
Electronics Spectra - SMS Lucknow
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<strong>SMS</strong> Institute of Technology, L ucknow<br />
Department of <strong>Electronics</strong> & Co mmunication<br />
The latter uses a simple optic al receiver<br />
to decode the incoming message.<br />
For uplink communication (dust<br />
to BST), the base station poin ts an<br />
un-modulated laser beam at a node,<br />
which in turn modulates and reflects<br />
back the beam to the BST. For this,<br />
the dust nodes are equipped wi th a<br />
Corner Cube Retro Reflector (C CR).<br />
The CCR has the property that any<br />
incident ray of light is reflected back<br />
to the source under certain co nditions.<br />
If one of the mirrors i s misaligned,<br />
this retro reflection property<br />
is spoiled. The Smart Dust CCR has an<br />
electrostatic actuator that can deflect<br />
one of the mirrors at kilohertz rates.<br />
Using this actuator, the incident laser<br />
beam is “on-off” modulated and reflected<br />
back to the BST.<br />
A) Active Laser based<br />
Communication<br />
Active optical communication typically<br />
uses an active-steered laser-diode<br />
based transmitter to send a collimated<br />
laser beam to a base station.<br />
This system contains a semicon ductor<br />
laser, a collimating lens and a beamsteering<br />
micro-mirror as shown in Figure<br />
2. Active optical communic ation<br />
is suitable for peer-to-peer communication,<br />
provided there exist a line of<br />
sight path between them. Using<br />
MEMS technology, the components of<br />
the active communication netwo rk<br />
can be made to be small enough to<br />
fit into the smart dust motes.<br />
GPS maptor<br />
Maptor, the navigational gadge t<br />
is the combination of Map and Projector.<br />
It is used to project map on<br />
any desired surface. Its really portable<br />
due to its small size. The mos t discussed<br />
advantage of Maptor is that,<br />
we don't need any one's help on the<br />
way, even if we are lost.<br />
GPS Maptor is GPS included with<br />
Maptor. We know that GPS is Global<br />
Positioning System; it is a US space<br />
based Global Navigation Satellite System.<br />
It provides reliable positioning,<br />
navigation and timing services to<br />
worldwide users. Maptor gives the<br />
combined effect of two technologies.<br />
As a result of the above said combination<br />
we can locate our cur rent<br />
position on the map with the help of<br />
a red arrow that points the location.<br />
Another advantage is the map pro-<br />
One of the disadvantages of th e<br />
active transmitter is its relatively high<br />
power consumption. This leads to the<br />
use of active optical communic ation<br />
for short duration burst-mode communication<br />
only. In order to minimize<br />
the power consumption, the act ive<br />
transmitter should have some protocol<br />
to aim the beams toward the receiver,<br />
for example, using directional<br />
beam and an active beam-steeri ng<br />
mechanism. These components<br />
would make the design of the d ust<br />
mote more complicated.<br />
B) Fiber-optic communication<br />
Fiber-optical communication em -<br />
ploys semiconductor laser, fiber cable<br />
and a diode receiver to gener ate,<br />
transfer and detect the optical signal.<br />
Its most of the characteristics matches<br />
with that of passive optical communication.<br />
The relatively small size of the<br />
optical transceiver is employe d with<br />
low-power operation. Each dust mote<br />
does not need to have an on bo ard<br />
light source to transmit the data. By<br />
the using MEMS technology, Cor ner<br />
cube retro-reflector is employ ed on<br />
each dust mote to modulate upl ink<br />
data to base station.<br />
APPLICATION OF<br />
SMART DUST<br />
It is very hard to detect the presence<br />
of the Smart Dust and it is even<br />
harder to get rid of them once deployed.<br />
Moreover it does not c ost<br />
jection is easily viewable even in day<br />
light. This concept is designed by Jin-<br />
much so can be densely deploye d.<br />
Due to the above-mentioned fea -<br />
tures, Smart Dust can be used in varied<br />
application fields. These are as follows:<br />
1) Environmental protection (identification<br />
and monitoring of pollution).<br />
2) Habitat monitoring (observing the<br />
behavior of the animals in the re<br />
natural habitat).<br />
3) Military application (monitoring activities<br />
in inaccessible areas , accompany<br />
soldiers and alert them<br />
to any poisons or dangerous biological<br />
substances in the air).<br />
4) Indoor/Outdoor Environmental<br />
Monitoring<br />
5) Security and Tracking<br />
6) Health and Wellness Monitoring<br />
(enter human bodies and check<br />
for physiological problems)<br />
7) Power Monitoring<br />
8) Inventory Location Awareness<br />
9) Factory and Process Automation<br />
10) Seismic and Structural Monitoring<br />
11) Monitor traffic and redirecting it.<br />
There are many ongoing researches<br />
on Smart Dust, the ma in<br />
purpose of these researches is to<br />
make Smart Dust mote as small as<br />
possible and to make it available at as<br />
low price as possible. Soon we will see<br />
Smart Dust being used in varied application<br />
from all spans of life.<br />
<br />
Priyanka Shukla<br />
EC - III year<br />
Sun Park and Seon-Keun Park<br />
to make a new wave in the<br />
gadget industry.<br />
The GPS Maptor combines<br />
GPS facility for maps, locations<br />
and directions capsulated<br />
in a mini projector. This<br />
gadget is really a handy one<br />
with its awesome shape.<br />
Moreover different projectors<br />
are available like Nokia<br />
Cellphone projector and<br />
Explay Handheld Projector,<br />
but still this new design may<br />
seem to be good for those<br />
who don't require the combination<br />
of cellphone and GPS<br />
navigation. Actually this device<br />
is really a boon to the<br />
tourists and for those who love travelling.<br />
<br />
25 <strong>Electronics</strong> <strong>Spectra</strong>, 2010