This document provides an overview of wireless sensor networks (WSNs). It describes the architecture of WSNs including sensor nodes, transceivers and controllers. It discusses different types of WSNs such as terrestrial, underground, underwater, multimedia and mobile WSNs. It also covers WSN topologies, characteristics, applications and limitations. The key aspects of WSNs are that they are made up of spatially distributed sensors to monitor environmental conditions and wireless connectivity is used to transmit sensor data to a central location for processing.

1. Submitted By:
Muhammed Ashraf Vaishnav P
Muhammed Aslam P M Rahul K H
Subin Sankar Akshay P
Nibin P Manu Prasad K
Sreerag
Wireless Sensor Network

2. CONTENTS
• INTRODUCTION
• ARCHITECTURE OF WSN
• WSN NETWORK TOPPOLOGIES
• TYPES OF WSN
• TERRESTRIAL WSN
• UNDERGROUND WSNs
• UNDER WATER WSNs
• MULTIMEDIA WSNs
• MOBILE WSNs
• WSNs vs Mobile Ad Hoc Networks
• LIMITATIONS OF WSNs
• APPLICATIONS OF WSNs
• CONCLUSION

3. INTRODUCTION
• Wireless sensor network (WSN) refers to a group of spatially dispersed and
dedicated sensors for monitoring and recording the physical conditions of the
environment and organizing the collected data at a central location.
• WSNs measure environmental conditions like temperature, sound, pollution levels,
humidity, wind, and so on.
• These are similar to wireless ad hoc network in the sense that they rely on wireless
connectivity and spontaneous formation of networks so that sensor data can be
transported wirelessly.
• The development of wireless sensor networks was motivated by military
applications such as battlefield surveillance
• today such networks are used in many industrial and consumer applications, such
as industrial process monitoring and control, machine health monitoring, and so on

4. ARCHITECTURE OF WSN

5. • A Sensor is a device that responds and detects some type of input from
both the physical or environmental conditions, such as pressure, heat,
light, etc.
• The output of the sensor is generally an electrical signal that is
transmitted to a controller for further processing.
• The data is forwarded through multiple nodes, and with a gateway, the
data is connected to other networks like wireless ethernet

6. WSNs TOPPOLOGIES
For radio communication networks, the structure of a WSN includes various topologies
like the ones given below.

7. Wireless Sensor Nodes
• Sensor
 A transducer
 converts physical phenomenon e.g. heat, light, motion, vibration, and sound
into electrical signals
• Sensor node
 basic unit in sensor network
 contains on-board sensors, processor, memory, transceiver, and power
supply
• Sensor Network
 consists of a large number of sensor nodes
 nodes deployed either inside or very close to the sensed phenomenon

8. Architecture of Sensor Node
Transceiver
Micro
-Controller
External Memory
ADC
Sensor 1
Sensor 2

9. Characteristics
• Power consumption constraints for nodes using batteries or
energy harvesting
• Ability to cope with node failures (resilience)
• Mobility of nodes
• Heterogeneity of nodes
• Scalability to large scale of deployment
• Ability to withstand harsh environmental conditions
• Ease of use
• Cross-layer design

10. TYPES OF WSNs
• Terrestrial WSNs
• Underground WSNs
• Underwater WSNs
• Multimedia WSNs
• Mobile WSNs
Depending on the environment, the types of networks are decided so that those can
be deployed underwater, underground, on land, and so on. Different types of WSNs
include:

11. 1. Terrestrial WSNs
• Terrestrial WSNs are capable of communicating base stations efficiently
• And consist of hundreds to thousands of wireless sensor nodes deployed
either in unstructured (ad hoc) or structured (Preplanned) manner.
• In an unstructured mode, the sensor nodes are randomly distributed
within the target area that is dropped from a fixed plane.
• The preplanned or structured mode considers optimal placement, grid
placement, and 2D, 3D placement models.
• In this WSN, the battery power is limited; however, the battery is
equipped with solar cells as a secondary power source.
• The Energy conservation of these WSNs is achieved by using low duty
cycle operations, minimizing delays, and optimal routing, and so on.

12. 2.Underground WSNs
• The underground WSNs networks consist of a number of sensor
nodes that are hidden in the ground to monitor underground
conditions.
• To relay information from the sensor nodes to the base station,
additional sink nodes are located above the ground.
• The underground wireless sensor networks are more expensive
than the terrestrial WSNs in terms of deployment, maintenance,
and equipment cost considerations and careful planning.

13. • Sensor nodes in underground WSNs have limited battery power and are difficult to
recharge.
• The underground environment makes wireless communication challenging due to high
levels of attenuation and signal loss.

14. 3.Under Water WSNs
• More than 70% of the earth is occupied with water.
• These networks consist of a number of sensor nodes and vehicles
deployed under water.
• Autonomous underwater vehicles are used for gathering data from
these sensor nodes.
• . A challenge of underwater communication is a long propagation
delay, and bandwidth and sensor failures.

16. 4.Multimedia WSNs
Multimedia wireless sensor networks have been proposed to enable tracking and
monitoring of events in the form of multimedia, such as imaging, video, and audio.

17. • These networks consist of low-cost sensor nodes equipped
with microphones and cameras.
• These nodes are interconnected with each other over a
wireless connection for data compression, data retrieval and
correlation.

18. 5.Mobile WSNs
• A mobile wireless sensor network (MWSN) can simply be defined as a
wireless sensor network (WSN) in which the sensor nodes are mobile.
• MWSNs are a smaller, emerging field of research in contrast to their
well-established predecessor
• These networks consist of a collection of sensor nodes that can be
moved on their own and can be interacted with the physical
environment.
• The mobile nodes have the ability to compute sense and communicate.
• MWSNs have various applications such as economics, environmental
monitoring, mining, health care, and tactical military surveillance.
• The major hardware constraints are limited battery power and low-cost
requirements.

19. Architecture

20. Applications of WSNs
• Transportation and logistics
• Industrial applications
• Precision agriculture and animal tracking
• Environmental monitoring
• Urban terrain tracking and civil structure monitoring
• structure monitoring Entertainment
• Entertainment
• Security and surveillance
• Health care (health monitoring, medical diagnostics)
• Smart grids and energy control systems
• Smart buildings (e.g. indoor climate control)

21. Limitations of WSNs
• Possess very little storage capacity – a few hundred kilobytes
• Possess modest processing power-8MHz
• Works in short communication range – consumes a lot of power
• Requires minimal energy – constrains protocols
• Have batteries with a finite life time
• Passive devices provide little energy

22. Conclusion
• WSNs possible today due to technological
advancement in various domains
• Envisioned to become an essential part of our
lives
• Design Constraints need to be satisfied for
realization of sensor networks
• Tremendous research efforts being made in
different layers of WSNs protocol stack

23. Thank you