MIS TERM PAPER

on

SMART DUST

THE MIGHTY MINIATURE

KODATI SOUJANYA

VGSOM, IIT KGP

MBA 2010-12

10BM60039

ABSTRACT

.

Most of us think dust is allergic but time has now come where dust will be smart like a fully functioning

computer. Smart Dust, the future mobile wireless sensor networks technology is making its way from

the research laboratory into the enterprise. Smart dust is the combination of digital circuitry, laser-

driven wireless communication technology and tiny wireless microelectromechanical sensors and can

be distributed in large numbers over an area to monitor everything from light to vibrations .This mainly

focuses on reduction of power consumption, cost and size. Smart dust nodes are also known as

motes which are usually the size of a grain of sand. Owing to such small dimensions, these motes

enable a lot of applications like military, climatic and environment control, building safety and

automation, security systems and many others.

INTRODUCTION

The basic idea of Smart Dust emerged with the miniaturization of conventional sensors and unison of

wireless-communications technology to form self-organizing, dynamic network devices that can used

for the delivery of a stream of data from the sensors. The objective of the Smart Dust devices or

motes lies in integrating the power-supply, sensor , computing and communication functions into a

single silicon platform that can analyze, collect and store data and then create an intelligent response.

This is of ultra low volume and light in weight such that it can remain suspended in air like any other

particle. The energy required in transmitting and processing the data is quite less, in the order of nano

Joules.

The advancements made today in the field of hardware technology and engineering design have

made it possible to integrate three key areas of technologies: digital circuitry, laser-driven wireless

communication and Microelectromechanical systems (MEMS). Mobile wireless sensor networks are

becoming very important for a variety of future applications. Future applications include tracking

enemy movements or source of a gunshot in military operations, battlefield surveillance, treaty

monitoring, transportation monitoring, scud hunting, IEDs detection, factory instrumentations, climatic

control, environmental monitoring of nerve gas like sarin or chemical spill, building safety and

automation, security systems. Others include virtual keyboard, inventory control, product quality

monitoring, smart office spaces, and interface for the disabled.

TECHNOLOGY REQUIREMENTS

Smart Dust technology comprises a single package with the components listed below integrated into it

- MEMS sensors, semiconductor laser diode, and MEMS beam– steering mirror for active optical

transmission, a MEMS corner-cube retro reflector for passive optical transmission, an optical receiver,

signal-processing and control circuitry, and a power source based on thick-film batteries and solar

cells. Each dust mote consists of one or more sensors, a power supply, digital and analog circuitry,

and a system for reception and transmission of data.

The proposed architecture should suffice the following requirements. Between the several dust motes

and the central transceiver , the mode of communication should be simplex, duplex or full duplex. The

downlink broadcast transmission rate from the central transceiver to dust motes should have a bit rate

in the order of several kbps. The uplink transmission from the motes to transceiver must allow each of

1000 dust motes to convey within one second about 1 kb of data, an aggregate throughput of 1 Mbps.

The central transceiver should have the capability to resolve the position of each dust mote with an

angular resolution of the order of 1/100 of the field of view. The operating range of the link should be

at least several hundred meters. The transceiver of the mote should consume an average power not

exceeding 1uW and occupy a volume of the order of 1 mm cube. The uplink and downlink should

have a low probability of interception.

Free-space optical transmission is considered to be the best alternative over radio frequency

transmission. In the near-infrared wavelength (400-1600nm) as well as in the visible region of the

spectrum, the free-space optical transmission would be an attractive alternative for the downlink and

uplink. Beyond low-power, passive communications, networking opportunities includes parallel read-

out, demand access and probe revisit rate. An on-off keyed signal is broadcasted to the collection of

dust motes by a single laser transmitter on the downlink. Each dust mote is equipped with a very

simple receiver consisting of a bandpass optical filter, and photodiode, a preamplifier, and a slicer.

This receiver would involve only low-speed baseband electronics, making it far simpler than radio

frequency (RF) counterpart. For the uplink, two alternatives for transmission exist offered by optics.

Each dust motes can equip with an active laser-diode-based transmitter.

A directional beam is employed and an active beam-steering mechanism is used by the dust mote for

the minimization of power consumption. The power can be efficiently managed alternatively, by

limiting the power consumption of each dust mote to microwatt level by powering on only when

necessary the various parts of the mote, and the solar cells could be used to consume as much

energy as possible in the presence of light. The optical links which have been well designed, using the

available LOS (line of sight) consume quite low energy per bit since the optical transceivers use

unsophisticated baseband analog and digital circuitry without modulators, demodulators and active

bandpass filters. These have short wavelength and a base station transceiver BTS along with a

compact imaging receiver which decodes the simultaneous transmissions from a large number of dust

motes at different locations within the receiver field of view. The corner-cube retroreflector (CCR)

which is a special MEMS structure enables the dust motes to use passive optical signals without the

supply of any optical power.

A free source operating system called TinyOS which is wireless is embedded into the sensor network

The various components of the OS include sensor drivers, network protocols and distributed services.

The event-driven execution model enable fine-grained power management besides allowing the

scheduling flexibility made necessary by the unpredictable nature of wireless communication and

physical world interfaces.A wide variety of sensor cards, and multiple hardware platforms are

supported which enable the development of smart sensor networks. It includes many-to-one collection

oriented, adhoc routing system.

TinyDB is a simple SQL like interface which specifies the data to be extracted along with rate at which

the data needs to be refreshed. It extracts the information from a network of TinyOS sensors. Data is

collected from the motes in the environment by it, and thereafter filters it and aggregates it together,

post which it routes it out to a PC. It accomplishes this through a power efficient in-network

Fig : Smart Dust mote containing micro fabricated sensors, optical receiver, active and passive optical

transmitter signal-processing and control circuitry and power sources. (Pister, 1998)

processing algorithms. A simple Java API is provided for writing PC applications which enable the

querying and extracting data from the network. It uses a simple graphical query builder and displays

the result using the API. It has several features like Metadata management, multiple and high level

queries, network topology and incremental deployment via query sharing .

An ad hoc network is deployed wherein the structure of the network changes through time. The

network can be set up arbitrarily and the motes being autonomous, self assemble easily into a

network of sensors. A one-to-many spanning tree root topology occurs mostly at the base station’s

interface to the sensor network. Information collected by the sensor is propagated to the base station.

Either raw sensor readings need to be collected or aggregate function values should be computed

over a set of sensor information which may be required ny certain applications. Intermediate nodes

help distant nodes in reaching the base station with the use of a multi hop network.

APPLICATIONS

Military and commercial applications:

Depending on the applications, individual dust motes may be affixed to objects that one wish to

monitor, or a large collection of motes may simply be dispersed and float at random throughout an

environment. The sensor readings are recorded and when queried thereupon, the readings are

reported via the optical mechanism. In military, the dust motes which contain magnetic, acoustic and

vibration sensors could be distributed across many square miles of territory to monitor the passage of

vehicles. The sensors could be delivered to the area by unmanned air vehicles UAV, artillery, or

distributed like seeds from moving vehicles. They could be interrogated by manned air vehicles (MAV)

or soldiers with modified binoculars. Chemical and biological sensor could be incorporated into the

dust motes to detect the use of chemical or biological agent in combat. Both military and commercial

could use to monitor the performance of critical parts of aircraft, vehicles, and manufacturing

equipment. This could dramatically reduce cost of maintenance. It could be deployed for stealthy

monitoring of a hostile environment for verification of treaty compliance. Acoustic vibrations or

magnetic field sensors could detect the passage of vehicles and other equipment. It could be used for

perimeter surveillance, or to detect the presence of chemical or biological agents on a battlefield.

They can track source of a gunshot in military operations, scud hunting, IED detection, battlefield

surveillance, nerve gas detection and chemical spill, and haul munitions.

Geological and Biological Research :

Smart Dust can be used over a region to record data for geophysical, meteorological or planetary

research. It may be employed to perform measurement in environments where wired sensors are

unusable or lead to measurement error. Examples include instrumentation of semiconductor

processing chambers, rotating machinery, wind tunnels and anechoic chambers. In biological

research, the movement, habits and environment of insects or other small animals can be monitored.

Measurement of Humidity :

The humidity in a nuclear waste repository can be measured because the mote is so small and can

operate for longer periods without wires and send data from locations where large device would not

be possible.

Automation:

It can be used in building

automation like

monitoring light control,

heat, ventilation and air

conditioning and energy

management. Computers

will turn off lights and

climatic control in empty

rooms. Air conditioners

that cool servers can be

automatically shut off and

turned on again when the

servers get too hot during

peak energy usage

times. Motes can be

attached to every

electrical wire throughout

an office building and the

induction sensor can

detect power

consumption on that

individual wire and down

to the individual outlet

can be observed.

Without human

intervention, the

monitoring of the

condition of essential

equipments on a

continuous basis will

provide critical data

collection in industrial

automation by installing

motes at critical points.

The motes can be

applied for the reduction

of downtime and enhancement of safety in a chemical plant that utilizes pipes to transport acidic or

abrasive liquids,. To prevent accidental chemical releases, plant operators must routinely inspect

pipes and this is labour intensive for pipes covered with insulation and pipes located in confined

areas. Several corrosion-detecting motes would be placed on the piping throughout the plant and they

would send data to a central monitoring station. The plant manager is benefitted by having up-to-date

status information of all piping and can have the advantage of avoiding cost of manual inspection.

Agriculture :

In agriculture sector, the temperature of air can be monitored across a vineyard, which helps in

protecting the crops from frost damage. Motes sensitive to temperature would be scattered on the

vineyard and produce long-term data, which will help the farmer to target specific plants for frost

control measure such as misting the plants with water. Grapes can be harvested more productively

and use of pesticides and fungicides would be reduced, over watering can be avoided, precision

harvesting will be enhanced, and plants’ growth and disease resistance will be monitored closely . It

can be used to monitor humidity and temperature to assess the freshness of foods stored in the

refrigerator or cupboard. It can monitor and capture irrigation needs data, soil pH and salinity levels .

Foodstuffs could be dusted with motes sensitive to moisture or acidity, which reports it when the food

is past it “best by” date.

Security :

In the field of security, motes could be used for surveillance, port tracking and container security.

Manufactured items like tiles, walls, and furniture can be embedded with smart dust to monitor and

collect information. It could be fitted with miniaturized microphones or tempest attack technology - a

tempest attack being an attempt to detect the distinct electromagnetic signal a computer gives out

each time a key is pressed used in undetectable spying devices.

Entertainment :

Motes also find vast variety of application in games and other forms of entertainment. A mote can be

glued on each fingernail in a virtual keyboard and accelerometers in the motes will sense the motion

and orientation of each of the fingertips and talk to the computer. The same idea could be extended to

the case of playing the piano or gesturing in sign language, wherein the handheld computer translates

hand gestures into music and speech.

Seismology :

It can be used for modelling earthquake damage. The motes provide information about collapse

potential, on-going information about the structural condition and early warning of inadequate safety

from a variety of causes. It can be used to monitor an area which is seismically active (like Dead Sea

which has seismic behaviour below sea level). It can also monitor archaeological preservations like

the Meseba site in Israel by scattering swarms of motes around large pieces of the mountain that

could fall off on people.

Forest Fires evasion :

It can also be used to detect fires. Forest service personnel would drop the motes from an airplane

and the motes self-organize into a network. In the event of a fire, the unusual temperature rise in its

zone is noticed by a mote which alerts neighbouring motes that will in turn notify other motes in the

network. The motes will then notify a central monitoring station of the fire and the location of the mote

that sensed it. This information provided to the fire fighters well within time along with the approximate

location helps them to combat the situation when the intensity of the fire is quite small.

Warehousing :

In a warehouse, motes can be used to have a container communicate with a box, which transmits

information to a palette. The palette sends the signals to a truck, and thereafter the truck sends the

information to a warehouse, which then relays the collective data to the Internet. In that way

companies can know about their products irrespective of time and location. The various assets in the

warehouse can be thus tracked.

Medicine :

In medicine it can be used to monitor the vital signs of elderly and sick people and also used for

tracking patients in a hospital room. Smart Dust will be placed throughout the body that will

continuously monitor the health of individuals, and in the bathroom to give physical examination every

day. When one brushes his or her teeth, the toothbrush takes the blood pressure and look for cavities.

When a person looks in the mirror, a little camera will look at the eyes to check for diabetes or

hardening of the arteries or any of the diseases that can be detected by looking at the eyes. By

putting the motes on the face of a quadriplegic’s it can monitor the eye movements and facial

gestures and assist them in operating a wheelchair or using computational devices. This will produce

a whole family of interfaces for the disabled. It can precisely and accurately monitor tiny muscular

movements in patients.

In biological research it is helpful to monitor the internal processes and movements of insects or other

small animals. A biologist can use mote that senses position and temperature by equipping an

endangered animal with a collar. The mote extracts data from the sensors when the animal moves

around. The data is then transmitted to the biologist through the ad hoc network formed by the motes

Others :

Other applications include factory instrumentations, climatic control, environmental monitoring of

chemical spill, building safety and automation, security systems, virtual keyboard, inventory control,

product quality monitoring, smart office spaces, and interface for the disabled

ISSUES AND CONCERNS

The development and use of Smart Dust raises some concerns. These include privacy issues,

potential system security weakness, the need for standards, and then environmental impact.

Privacy issues :

The issue mostly to be concerned about is the privacy issue, owing to its use for detrimental and

unethical purposes. Another concern is when individuals and governments use it to monitor people

without their knowledge. It might also fall a prey to corporate espionage.

Security issues :

Since smart dust motes on the network can be reprogrammed, they are prone to security concerns

similar to that of computers on the Internet. In spite of the mote identity verification algorithms in the

TinyOS operating system making it difficult, this mote software features could be exploited by hackers

and eavesdroppers. In applications where sensitive data is gathered, system designers should be

cautious of the risk of the data being compromised. Foreign governments, terrorist organization,

criminals, and industrial spies could use high tech motes to spy.

Environmental Issues :

The motes which fly around in the atmosphere can have a serious environmental effect and can

cause a serious problem. After motes are sprinkled in a remote or desolate area to accomplish a

monitoring function, it is not easily retrieved. If a mote fails and is consequently abandoned or lost,

there is an environmental impact. A mote’s environmentally unfriendly components include integrated

circuits, lithium battery and a printed circuit board. Some motes use radioactive power sources and

can cause environmental concerns. It is not assured that used motes with radioactive power sources

would be retrieved and disposed of properly. The society may raise a concern to living and working in

close proximity to radiation sources. The potential ill effects on the environment and health raise

concerns.

CONCLUSION

The Smart Dust technology has applications where benefits and uses outweigh the concerns and

hazards. There is growing feeling among researchers of its huge impact on society. The motes could

be powered by solar light, barometric pressure and vibrations in the wall. The ecosystem that is

necessary for mainstream and industrial and business applications is being developed. Smart Dust

technology is progressing rapidly and working motes with reduced size and efficient power supply is

expected in couple of years. It is hoped that the objectives of the Smart Dust project will be realized,

and commercialization and subsequent use will be widespread throughout society. In the military for

example it could offer an alternative and cheaper way to monitor enemies by reducing cost, risk to

human life and performance. In the future there would be a time where millions of motes are

embedded in almost everything which would be able to sense, compute and communicate with each

other using ultra low power.

REFERENCES

Pister, K. S. J. Smart Dust Autonomous Sensing and Communication in a cubic

millimeters. http://robotics.eecs.berkeley.edu/~pister/SmartDust/

Singer, M. Smart Dust Collecting in the Enterprise.

http://siliconvalley.internet.com/news/print.php/3098551

Manjoo, F. Dust Keeping the Lights Off Retrieved

http://www.wired.com/news/technology/1,44101-0.html

faculty.ed.umuc.edu/~sdean/ProfPaps/Bowie/T3-0506/Atuobi.pdf

Nanotechnology Now. Your Gateway to Everything Nanotech (n.d.).

http://www.nanotech-now.com/smartdust.htm

Brain, M. (n. d.). How Motes Work.

http://computer.howstuffworks.com/mote.htm