WIRELESSSENSORSNETWORK

anywhere and everywhere.

omnipresentS en s in g Z o n e w ith s en s o r - c o o r d in a to r ,s en s in g - c o llab o r a to r s , an d b ac k b o n e n o d es

L ev el- 0 to L ev el- 1 b ac k b o n e

L ev e l- 1 to L ev el- 2 b ac k b o n e

S en s o r C o o r d in a to r

S en s in g n o d es

L ev el- 1 Bac k b o n e n o d e

L ev el- 2 Bac k b o n e n o d e

S en s in g Z o n e M em b er s h ip

A sensor network is an infrastructure comprised of sensing (measuring), computing, and communication elements that gives an administrator the ability to instrument, observe, and react to events and phenomena in a specified environment

The environment can be the physical world, a biological system, or an information technology (IT) framework.

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WIRELESS SENSOR NETWORK

WSN NODE COMPONENTSLow-power processor.Limited processing .Memory.Limited storage.Radio.Low-power.Low data rate.Limited range.Sensors.

sensors: temperature, light, etc.Cameras, microphones.Power.

Sensors

Processor

Radio

Storage

POWER

WSN device schematics

Sensor networking is a multidisciplinary area that involves, among others,

radio and networking ,signal processing,

artificial intelligence, database management ,

systems architectures for operator-friendly infrastructure administration,resource optimization ,power management algorithms ,

and platform technology (hardware and software, such as operating systems)

WHAT IS ZIGBEE?

Technological Standard Created for Control and Sensor Networks

Based on the IEEE 802.15.4 Standard Created by the ZigBee Alliance Named for erratic, zig-zagging patterns of bees

between flowers Symbolizes communication between nodes in a

mesh network

ENGINEERINGDESIGNRESEARCHCHALLENGES

Engineering Challenges ●Identification of several simultaneous

events &reliable correlation of information

from neighboring nodes ●Classification of objects & events

●Improved integration of different sensor types

●Miniaturization & better robustness of sensors

●Common formats & standardsfor sensor data communication

NETWORK ARCHITECTURENetwork should be scalable

Flexible and hierarchical architecturesshould accommodate the requirements of both heterogeneous and homogeneous infrastructure

flat single-tier network of homogeneous sensor nodes

Multi-tier heterogeneous approaches (clustering/partitioning)resource-constrained low-power elements are in charge of performing simpler tasks, such as detecting scalar physical measurementsresource-rich high-power devices (such as gateways) perform more complex tasks

DESIGN CHALLENGES (CONT’D) Heterogeneity.

Devices with varied capabilities. Different sensor modalities. Hierarchical deployments.

Adaptability. Adjust to operating conditions and changes in

application requirements. Security and privacy.

Potentially sensitive information. Hostile environments.

2012Research Challenges

●Increase WSN usability, flexibility & security ●Security: reputation approaches

●Endurance: energy harvesting, efficiency ●Coverage & connectivity improvement:

sensing & communication range(yet covert, small EM emission)

●Information processing, fusion & knowledge:related to coverage for reliable correlationof info across space & timeto perform data mining, knowledge engineering

●Optimum communications schemes ●Optimum protocols

●Optimum Hierarchical deployments.