2. What is Wireless Sensor
Networks?
WSN combines sensing, computation,
and communication into single tiny
device called sensor node.
Group of sensors linked by wireless
media to perform distributed sensing
task
3. What is Sensor Node?
Sensor is a device, which senses
information and passes it to the mote.
Figure : Wireless sensor network device
5. Architecture of a Sensor
Node
A Power unit (Battery)
Computational logic & Storage
Sensor Transducer
Communication
Components of Sensor Node
1. HARDWARE
6. Architecture of a Sensor
Node
Figure : The architecture of a sensor node.
Contd..
10. Available Wireless Technologies
Standard Data Rate Range Power
Consumption
ZigBee
(802.15.4)
20 kbps to
250 kbps
Up to 10 m Ultralow
Bluetooth
(802.15.1)
Up to 3 mbps 1m to 100 m low
Wi-Fi
(802.11)
54 mbps 45 m to 90
m
Medium
Contd…
11. Need of Security
WSNs are becoming a cost effective,
practical way to go about deploying
sensor networks.
Protecting confidentiality, integrity
and availability of communications.
Large range of applications from
civilian to military purposes.
12. Need of Security
• Obstacles:
Very-Limited Resources
Unreliable Communication
Unattended Operations
• Attacks:
Sybil Attack
Traffic Analysis Attacks
13. Need of Security
• Attacks:
1) Sybil Attack:
Introduced by “Brain Zill” in 2002
Subverted by Foreign identities in
peer-to peer Network
2) Traffic Analysis
Intercepting & Examine messages to
deduce info. from patterns in
Communications.
Able to detect Encrypted messages but
Not able to Decrypt it.
14. Security for Sensor Network
SMACS :
Self organizing medium access
control for sensor networks.
Encryption:
Encoding info. in such a way that
hackers can’t read it, but authorized
one can.
Cryptography & Steganography:
Techniques for Secure
Communication in presence of Third
parties.
15. Application of WSN
Home and Office Applications
Environmental Applications
Medical & Health Applications
Military Applications
16. Advantages
Implementation cost is cheaper
than wired network
Ideal for non-reachable places
It avoids hell lot of wiring
It can accommodate new devices
at any time
17. Disadvantages
Less secure because hacker's laptop
can act as Access Point.
Lower speed as compare to wired
networks.
Affected by surrounding. E.g.: walls
(blocking), microwave oven , far distance
18. Conclusion
The low cost, flexibility, fault tolerance,
high sensing fidelity and rapid deployment
makes way for new applications on remote
sensing.
Realization needs to satisfy the constraints
such as scalability, topology changes,
power consumption, environment etc.
New wireless ad hoc networking
techniques are required to overcome this
constraints.
19. References
Wireless Sensor Network (KAZEM
SOHRABY, DANIEL MINOLI,
TAIEB ZNATI)
System Architecture for Wireless
Sensor Networks (Jason Lester Hill)
http://today.cs.berkeley.edu/800dem
o/.s
http://www.powerstream.com
http://www.wikipedia.com