A First Introduction to

Wireless Sensor Networks

Aparna S BalanVidya Academy of Science and Technology,

Thrissur -680 501, India

16 July 2010

Wireless Sensor Networks

→ Number of sensors spread across a geographical area.

→Each sensor has → wireless communication capability

→ some level of intelligence

A

B

KC

D

E

H

I

JSink

Control

SignalProces

sorSensors

Wireless

Transmitte

r/ Receiver

Processing And Decisio

n Making

Schematic of Node

Power

Classification of Sensor Networks

→Proactive → provides the snapshot of the relevant parameters at regular intervals

→Reactive→ nodes react immediately to the events

Protocols for Sensor Networks

→To avoid collision at a time only one node will transmit

→ Static channel allocation→If N node, bandwidth is divided into N equal partitions

→ Dynamic channel allocation

→No fixed assignment of bandwidth

Protocols for Sensor Networks

→ Directed Diffusion→ SPIN→ Hierarchical Routing→ Cluster-Based Routing→ LEACH

Base Station

Second Level Cluster HeadFirst Level Cluster HeadSimple Sensor Nodes

Goal of WSN

→ Determine value of some parameters

→ Detect the occurrence of events

→ Classify a detected object

→ Track an object

WSN requirements

→Large number of sensors

→Low energy use→ Network self-organization

→ Collaborative signal processing

→ Querying ability

Applications

→ Defense Application→ Crisis-Management Applications

→ Detect Environmental changes

→ Motor Vehicle traffic monitoring

Thanks …