John A. Stankovic
Presented by:
Sandeep reddy allu
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The technologies for wireless communication,
sensing, and computation are each progressing
at faster and faster rates. Notably, they are also
being combined for an amazingly large
multiplicative effect. It can be envisioned that the
world will eventually be covered by networks of
networks of smart sensors and actuators. This
fact will give rise to revolutionary applications.
However, to make this vision a reality, many
research challenges must be overcome. This
paper describes a representative set of new
applications and identifies several key research
challenges.
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Wireless sensor and actuator networks
(WSANs)
new technology with great potential for improving many
current applications as well as creating new revolutionary
systems in areas such as global scale environmental
monitoring, precision agriculture, home and assisted living
medical care, smart buildings and cities, industrial
automation, and numerous military applications
WSANs - large numbers of minimal capacity sensing,
computing, and communicating devices and various types of
actuators .
These devices operate in complex and noisy real world, realtime environments
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These both are highly related fields but not identical.
embedded systems emphasize form factor, cost and
other constraints, while real-time systems emphasize timing
properties.
Future Applications
global scale environmental monitoring and
control
social participatory computing,
continuous birth-to-death health care.
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At present a lot of sensors exist around the world
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These sensors focus mainly on single problem
such as effect of tides on barrier islands off the
coast of VA or tornado info in central part of USA.
These are separated by 100’s and 1000’s of
meters .
In WSAN tech have potential of dense and flexible
coverage with correlation across many WSAN’s .
which leads to new understanding of
environmental conditions. These are seperated
by cms or mtrs.
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This will help in micro agriculture to control
pesticides and fertilizers usage amount.
When unexpected environmental disasters occur
these sensors are used to collect immediate data
which will help in rescue.
We can collect data from different lakes using this
sensors and we can calculate the pollution effect
on water bodies and also effect on fishes in those
water bodies by performing data mining we can
generate patterns which help in saving water life
and also reduce water pollution.
When we have a global WSAN’s we will have a
better understanding of how a particular change
in weather at one place can effect others regions
on earth
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ubiquity of WSAN technology will include devices worn and
carried by individuals as well as many emplaced systems in all
our surroundings.
This access to real time data will effect the day to day
schedule of human. Every individual will be able to track
commuting delay s and minimize delays.
Traffic can be maintained by real time info from the sensors
to reduce congestion .
This includes family groups, work groups, medical groups,
and social groups. Preferences can be automatically
incorporated into these activities. Automatic notifications for
special social events such as a concert or sales on products
currently of interest to an individual will be routine
This will lead to a Happier lifestyle.
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WSANs can be implemented on large scale for
medical care
We can create and maintain a separate account
for each individual when they are born and there
health position can be updated regularly by using
sensors in cloths and instant treatment can be
provided to the user when ever there is some
change occurred health .
Long term health information on individuals will
enable dramatic improvements in their care as
well as over all understanding of a patient .
.This will improve health of every individual .
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From Raw Data to Knowledge:
From world wide spread WSAN ‘s large amount of data is
collected continuously .
But major task is to filter the data by implementing new
techniques to convert raw data to usable knowledge .
Example:
If we collect raw data from a person regarding his diet
,respiration ,heart beat ,signs of depression etc we can
convert this data to knowledge and we come to a decision
about health of that person.
Other challenge is data interpretation and the formation of
knowledge include addressing noisy physical world data and
developing new inference techniques to filter data to improve
confidence for data.
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Given that a very large number of WSANs will exist, with each
providing many real time sensor streams, it will be common for a
given stream of data to be used in many different ways for many
different inference purposes.
But there no inference method which is 100 % correct.
This uncertainty in interpreted data will cause user not to trust
on system.
Trust is at the crux of next generation WSAN technology. Security
and privacy are essential elements of trust, and these are
discussed in their own sections.
Without these basic underlying system-level capabilities,
further inference might be operating with wrong or too much
missing data, resulting in wrong conclusions. If these wrong
conclusions drive actuators, then serious safety problems can
occur. One approach is to ensure that all inferred information is
accompanied by a confidence level in the form of a probability
that the information is correct or incorrect .
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applications in WSNs typically initialize themselves by selforganizing after deployment
At the conclusion of the self-organizing stage, it is common for
the nodes of a WSN to know their locations, have synchronized
clocks, know their neighbors, and have a coherent set of
parameter settings, such as consistent sleep/wake-up schedules,
appropriate power levels for communication, and pair-wise
security keys
DETERIORATION PROBLEM: deterioration problem is with clock
synchronization.
Over time, clock drift causes nodes to have different enough
times
More and more nodes may become out of place over time to
result in application failures.
Note that control of actuators can also deteriorate due to their
controlling software and protocols, but also due to physical
wear and tear.
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To over come this problem new approaches to be implemented
for a robust system operation.
This means Developing reliable code, debugging techniques,
fault tolerant and general health monitoring services
Openness:
Mostly sensor based systems are closed systems.
Ex: cars , airplanes etc.
These systems and other WSAN systems are expanding rapidly .
General info about these cars and airplane such as maintenance
information is sent to manufactures through sensors.
WSANs will enable an even greater cooperation and 2-way
control on a wide scale: cars (and aircraft) talking to each other
and controlling each other to avoid collisions, humans
exchanging data automatically when they meet and this possibly
affecting their next actions, and physiological data uploaded to
doctors in real time with real-time feedback from the doctor.
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Human interaction is an integral aspect of openness, and this
makes modeling extremely difficult. The scaling and
interactions across systems also dynamically change the
models and create a need for decentralized control. While
some work has been performed in areas such as stochastic,
robust, distributed, and adaptive control, these areas are not
developed well enough to support the degree of openness
and dynamics expected in WSAN.
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Major problem with WSAN is dealing with security attacks.
This is a critical issue because of minimal capacity devices .
Permanent random failures.
Redundancy in WSAN design to work even in face of failure.
Security attacks and recovery from attacks.
Strong detection capabilities – detect, diagnose, deploy
countermeasures .
self-healing features-better than complete secure system.
Mainframes Security solution are heavyweight computations
which is major challenge.
Quick response.
Healing with reprogramming.
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opportunities to violate privacy
privacy policies for domains.
System decision for granted or denied.
Requirements:
context information- time, space, physiological
sensing, environmental sensing, and stream-based noisy data
Evaluate data requester.
Need to represent high-level aggregating requests-avg
,min,max etc.
Privacy on request to parameters .
allow dynamic changes to the policies and keep track of
dependents.
Major problem- interacting with other systems, each having
own privacy policies.
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This paper focuses on future applications and research. For
readers interested in the individual open research questions
discussed, those particular sections contain references to
related works. This section presents several additional
comprehensive papers related to WSAN
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When WSANs cover the world, a new revolution similar to the
Industrial and Internet revolutions will occur. But robustness,
security, and privacy to co-exist—not an easy task!
Many other important topics targeting WSAN must also be
addressed including the following: heterogeneity, standards,
programming abstractions and languages, real-time stream
databases, middleware, operating systems, scaling,
composition theory and analysis, formal methods, the
wireless spectrum, wireless realities including interference,
real-time, system safety, design, analysis and debugging
tools, energy scavenging and power control, mobility, time
synchronization, location services, decentralized algorithms,
swarm computing, and signal processing. Simultaneously
addressing several of these issues in the context of WSAN will
produce many interesting research problems.
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Reputation-Based Beacon Trust System,” 2nd IEEE Int’l Symp.
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Dependable, Autonomic, and Secure Computing (DASC), 2006,
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[2] A. Woo, T. Tong, and D. Culler, “Taming the Underlying
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