WIRELESS SENSOR NETWORKS: AN OVERVIEW

Presented By: Saqib Naveed 07010656-071

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Introduction

A sensor network is composed of a large number of sensor nodes, which are densely deployed either inside the phenomenon or very close to it.

Random deployment Cooperative capabilities

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Applications of sensor networks temperature humidity vehicular movement lightning condition pressure soil makeup noise levels the presence or absence of certain kinds of

objects mechanical stress levels on attached objects the current characteristics such as speed,

direction, and size of an object

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Applications of sensor networksMilitary applications Monitoring friendly forces, equipment

and ammunition Battlefield surveillance Reconnaissance of opposing forces and

terrain Battle damage assessment Nuclear, biological and chemical attack

detection and reconnaissance

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Applications of sensor networksEnvironmental applications Forest fire detection Flood detection Precision agriculture

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Applications of sensor networksHealth applications Telemonitoring of human

physiological data Tracking and monitoring patients and

doctors inside a hospital Drug administration in hospitals

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Applications of sensor networksHome applications

Home automation Smart environment

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Applications of sensor networksOther commercial applications Environmental control in office

buildings Interactive museums Managing inventory control Vehicle tracking and detection Detecting and monitoring car thefts

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Factors influencing sensor network design

Fault tolerance

Fault tolerance is the ability to sustain sensor network functionalities without any interruption due to sensor node failures.

The fault tolerance level depends on the application of the sensor networks.

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Factors influencing sensor network design

Scalability

Scalability measures the density of the sensor nodes.

Density = (R) =(N R2)/A

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Factors influencing sensor network designProduction costs

The cost of a single node is very important to justify the overall cost of the networks.

The cost of a sensor node is a very challenging issue given the amount of functionalities with a price of much less than a dollar.

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Factors influencing sensor network design

Hardware constraints

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Factors influencing sensor network designPower consumption

Sensing Communication Data processing

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Communication architecture of sensor networks

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Communication architecture of sensor networks

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Communication architecture of sensor networksApplication layer The three possible application layer

protocols are - Sensor management protocol (SMP) Task assignment and data

advertisement protocol (TADAP) Sensor query and data dissemination

protocol (SQDDP)

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Communication architecture of sensor networksTransport layer This layer is especially needed when

the system is planned to be accessed through Internet or other external networks.

No attempt thus far to propose a scheme or to discuss the issues related to the transport layer of a sensor network in literature.

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Communication architecture of sensor networksNetwork layer

Power efficiency is always an important consideration.

Data aggregation is useful only when it does not hinder the collaborative effort of the sensor nodes.

An ideal sensor network has attribute-based addressing and location awareness.

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Communication architecture of sensor networksData link layer The data link layer is responsible for

the medium access and error control. It ensures reliable point-to-point and point-to-multipoint connections in a communication network.

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Communication architecture of sensor networksMedium access control Creation of the network

infrastructure Fairly and efficiently share

communication resources between sensor nodes

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Communication architecture of sensor networksError control Forward Error Correction (FEC) Automatic Repeat Request (ARQ). Simple error control codes with low-

complexity encoding and decoding might present the best solutions for sensor networks.

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Communication architecture of sensor networksPhysical layer The physical layer is responsible for

frequency selection, frequency generation, signal detection, modulation and data encryption.

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Thank You Alls…..

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