This document discusses wireless sensor networks (WSNs), including their types, characteristics, architecture, middleware, standards, applications, challenges and future scope. WSNs consist of spatially distributed autonomous sensors that monitor physical or environmental conditions. They have constraints in terms of cost, size, topology and power. The document outlines the components and software architecture of WSNs, and examines issues like energy efficiency. It also explores common applications in areas like healthcare, pollution monitoring and home automation, along with ongoing challenges in hardware, software and large-scale deployment.

1. WIRELESS SENSOR
NETWORKS
Prepared by:
Abhinay Kumar Suraj (151210011)
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1
National Institute of Technology Delhi

2. CONTENTS
 Introduction
 Types of WSN
 Characteristics of a WSN
 Architecture components of a WSN
 Architecture of a WSN
 Characteristics of a middleware
 Concept of SOA for wireless networks
 Architectural issues
 Standards and Specifications
 Applications
 Challenges
 Advantages
 Disadvantages
 Future Scope
 Conclusion
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3. INTRODUCTION
 What is a wireless sensor network (WSN)…?
 Motivation of development
 Parts of a sensor node in the network
 Functions of a sensor node in the network
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Constraints
Cost Size Topology

4. SENSORS
 Sensor is a device, which senses information and
passes it to the mote.
 Development of sensors over the year
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5. TYPES OF WIRELESS SENSOR NETWORKS
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 Dense collection of nodes
 Ad-hoc
deployment
 Difficulty in network
maintenance
 Few and scarcely
distributed nodes
 Pre-planned deployment
 Lower network
maintenance
Unstructured WSN Structured WSN

6. CHARACTERISTICS OF A WSN
1. Self – Organization
2. Concurrency processing
3. Low cost
4. Restricted energy resources
5. Tiny
6. Small radio range
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7. SOFTWARE ENGINEERING
 Service oriented architecture
 Applications
- Sensor Applications
- Node Applications
- Sensor Network Applications
 Sensor Application - Readout of a sensor , local storage of the data.
It has full access to the hardware and is able to access the operating
system directly.
 Node Application - Application specific tasks and functions of the
middleware to build up and maintain the network
 Sensor Network Application - Main tasks and required services of
the entire network
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8. CHARACTERISTICS OF A MIDDLEWARE FOR
SENSOR NETWORK
 Middleware - software layer between operating system
and application
 Primary objective of a middleware
 A middleware has to be
1. Scalable
2. Generic
3. Adaptive
4. Reflective
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9. CONCEPT OF SOA FOR WIRELESS NETWORKS
 A simple use case can help determine the software
architecture.
 Example of a simple service architecture
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10. ARCHITECTURE OF NODE APPLICATION
STRUCTURE
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 Node software has 3 parts
1. Operating System which performs device-specific tasks
2. Sensor Driver which initializes the sensor hardware and performs
the measurements in the sensor
3. Host Middleware which organizes the co- operation of the
distributed nodes in the network
A sample sensor

11. OVERALL GENERAL ARCHITECTURE
 The general overall software architecture of the sensor
net is shown in the figure
 Individual nodes interact with the distributed
middleware layer to perform the functions dictated by
the sensor network application
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12. ARCHITECTURAL ISSUES
 Energy efficiency
 Network topology
 Failure in long range communication
 Increase in traffic decreases the lifetime
 Single tier and multi tier architecture disadvantages
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13. ARCHITECTURE – CLUSTER BASED
 Proposed to tackle the previous architectural issues
 Provides Quality of management (Qos)
 Dynamic architecture – cluster is a basic unit of software
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14. STANDARDS AND SPECIFICATIONS
 Predominant standards commonly used in WSN
communications include:
1. Zig Bee - Transmit data over long distances by passing
data through intermediate devices to reach more
distant ones
2. Bluetooth - Wireless technology standard for
exchanging data over short distances from fixed and
mobile devices by creating PANs’
3. 6LoWPAN - Defined encapsulation and header
compression mechanisms that allow IPv6 packets to be
sent to and received from over IEEE 802.15.4 based
networks
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15. AVAILABLE WIRELESS TECHNOLOGIES
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16. APPLICATIONS OF WSN
 Area monitoring
 Health care monitoring
 Air pollution monitoring
 Forest fire detection
 Landslide detection
 Water quality monitoring
 Natural disaster prevention
 Industrial monitoring
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17. TIER STRUCTURE OF WSN IN MEDICAL FIELD
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18. WSN:HOME AUTOMATION
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19. CHALLENGES
 Hardware :
1. Low cost
2. Tiny sensors
3. Lifetime maximization
4. Robustness and fault tolerance
5. Self-configuration
 Software :
1. Operating systems
2. Security
3. Mobility
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20. ADVANTAGES OF A WSN
 Avoids a lot of wiring
 Can accommodate new devices at any time
 Flexible to go through physical partitions
 It can be accessed through a centralized monitor
 Infrastructure
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21. DISADVANTAGES OF WSN
 Easy for hackers to hack a network
 Comparatively low speed of communication
 Gets distracted by various elements
 Costly at large
 Life of nodes
 Energy life
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22. FUTURE SCOPE
 More research work needs to be done in future.
 Needs to be implemented in a wireless sensor network
with mobile nodes.
 The effects of very large node densities need to be
investigated.
 The feasibility of using the clustering technique and data
aggregation needs to be tested in the same wireless
sensor network.
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23. FUTURE INTERNET
 Future of internet when a lot of IOT devices
participate.
 It will help current internet to scale further for future
need
 It will provides flexibility, promotes diversity, and
promises security and increased manageability
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24. CONCLUSION
As described, wireless sensor networks possess the
potential for many applications. The advance of
technology enabled the creation of prototype WSNs, but
the hardware and software both have a ways to go before
WSNs are practical, cost-effective, and usefully.
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25. REFERENCES
 www.wikipedia.org
 http://stakeholders.ofcom.org.uk/binaries/research/tec
hnology-research/wsn2.pdf
 http://www.researchgate.net/publication/228695105_S
ervice-
oriented_software_architecture_for_sensor_networks/f
ile/5046351a8ae5a75f8b.pdf
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