This document provides an overview of wireless sensor networks. It discusses key definitions, advantages, applications and challenges. Sensor networks can provide energy and detection advantages over traditional systems. They enable applications in various domains including military, environmental monitoring, healthcare and home automation. The document also outlines enabling technologies and discusses important considerations like network architectures, hardware components, energy consumption and optimization goals.

1. OVERVIEW OF WIRELESS
SENSOR NETWORKS:
 Key definitions of sensor networks.
 Advantages of sensor Networks.
 Unique constraints an challenges.
 Driving Applications.
 Enabling Technologies for Wireless
Sensor Networks.

2. Key Definitions of Sensor
Networks:
•Sensor
•Sensor node
•Network topology
•Routing
•Date-centric
•Geographic routing
•Geographic routing
•Collaborative processing
•In-network

3.  Uncertainty
 State
 Task
 Detection
 Classification
 Value of information or
information utility.
 Resource
 Sensor tasking

4.  Embedded operating system
(OS)
 Evaluation metric
 Node services
 Data storage

5. Advantages of Sensor Networks:
 Energy Advantage:
Psend ∝ rα Preceive

6.  Detection Advantage
 SNRr =
10 log Psource − 10 log Pnoise − 20
log r.
 Increasing the sensor density by a factor of k
reduces the average distance to a target by a
factor of .
 Increase in sensor density by a factor of k improves
the SNR at a sensor by 10 log k db.

7. Applications of wireless
sensor networks:
Military applications
 Monitoring inimical forces
 Monitoring friendly forces and
equipment
 Military-theater or battlefield
surveillance
 Targeting
 Battle damage assessment
 Nuclear, biological, and chemical
attack detection and more ...

8. Environmental applications
 Microclimates
 Forest fire detection
 Flood detection
 Precision agriculture and more ...
Health applications
 Remote monitoring of physiological
data
 Tracking and monitoring doctors and
patients inside a hospital
 Drug administration
 Elderly assistance and more ...

9. Home applications
 Home automation
 Instrumented environment
 Automated meter reading and more ...
Commercial applications
 Environmental control in industrial and
office buildings
 Inventory control
 Vehicle tracking and detection
 Traffic flow surveillance and more ...
Disaster relief applications
Precision agriculture

10. Enabling Technologies for
Wireless Sensor Networks:
 Hardware:
 Wireless Networking:
 Collaborative Signal Processing:
 Energy scavenging:

11. Challenges for WSNs
1.Characteristic requirements
2.Required mechanisms
1.Characteristic requirements:
 Type of service
 Quality of Service
 Fault tolerance
 Lifetime
 Scalability
 Wide range of densities
 Programmability
 Maintainability

12. 2. Required mechanisms
 Multihop wireless communication
 Energy-efficient operation
 Auto-configuration
 Collaboration and in-network
processing.
 Data centric
 Locality
 Exploit trade-offs

13. ARCHITECTURES:
Single-Node Architecture –
 Hardware Components
 Energy Consumption of Sensor Nodes
 Operating Systems and Execution
Environments,
Network Architecture –
 Sensor Network Scenarios
 Optimization Goals and Figures of
Merit
 Gateway Concepts.

14. Hardware Components
 Controller.
 Memory
 Sencor and actuqtors.
 Communication.
 Power supply.

15. Overview of main sensor node
hardware components

16. Transceiver operational states

17. Energy Consumption of
Sensor Nodes
 1. Operation states with
different power consumption.
 2. Microcontroller energy
consumption.
 3. Memory.
 4. Radio transceivers.

18. Operation states with different
power consumption:

19.  Eoverhead = tup(Pactive + Psleep)/2.
 Esaved =(tevent − t1)Pactive −
(τdown(Pactive + Psleep)/2 +
(tevent − t1 − τdown)Psleep).
 Eactive = Pactive(tevent − t1) .

20. Operating Systems and
Execution Environments:
 1. Embedded operating systems:
 2. Programming paradigms:
Concurrent Programming
(sequential prog model).
Process-based prog model
Event-based programming model

22. Network Architecture –
 Sensor Network Scenarios:
1.Types of sources and sinks.
2.Single-hop versus multihop
networks.
3.Multiple sinks and sources.
4. Three types of mobility.

23.  Source-a source is an entity in the
network that can provide information
 Sink- It is the entity where information
is required
 1.Neighbour node
 2.Hand held device (PDA)
 3.INTERNET

24. 2.Single-hop versus multihop networks.

25. 3.Multiple sinks and sources

26. 4. Three types of mobility.
 Node mobility.
 Sink mobility.
 Event mobility.

27. Optimization Goals and
Figures of Merit:
 1.Quality of service.
 2. Energy efficiency.
 3. Scalability.
 4. Robustness .(QoS +scalability )

28. Quality of service
LOW LEVEL ATTRIBUTES
 DATA TRANSMISSION
 DETECTION OF EVENT
 MODULATION TECHNIQUES
 CHANNEL

29. HIGH LEVEL QOS
ATTRIBUTES
 EVENT DETECTION/REPORTING
PROBABILITY
 EVENT CLASSIFICATION-ERRORS
 EVENT DETECTION DELAY
 MISSING REPORTS
 TRACKING ACCURACY

30. Energy efficiency.
 Energy per correctly received bits
 Energy per reported event
 Delay/energy trade off
 Network life time
Payload –the energy required to
transfer I bit of information

31. DESIGN PRINCIPLES FOR
WSN
 Distributed organization
 In network processing
 Adaptive fideility and accuracy
 Data centricity (address data, not
nodes)

32. Gateway Concepts:
 The need for gateways

33.  WSN to Internet communication

34.  Internet to WSN communication

35.  WSN tunneling:(Gateways can also
act as simple extensions of one
WSN to another WSN. )