Shahin Farshchi, Member, IEEE, Aleksey Pesterev, Paul Nuyujukian, Eric Guenterberg, Istvan Mody, and Jack W. Judy, Senior Member, IEEE,

” Structure of Wireless Sensors Network Based on TinyOS”IEEE TRANSACTIONS ON NEURAL SYSTEMS AND REHABILITATION ENGINEERING, VOL. 18, NO. 2, APRIL 2010

Presenter: Shao-Kai Liao

Adviser: Tsung-Fu Chien

Date: 12.7.2011

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OutlineOutline

IntroductionIntroduction

PurposePurpose

Methods & Methods & MaterialsMaterials

ConclusionsConclusions

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IntroductionIntroduction Structure of Wireless Sensor Network (WSN)

MEMS (Micro Electro Mechanical Systems)

Embedded system

Wireless communication

Distributed processing

Sensor technology

微機電系統 ( Micro Electro Mechanical Systems ， MEMS) 無線感測器網絡（ Wireless Sensor Network ， WSN ）

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IntroductionIntroduction

Application of Wireless Sensor Network

High application values in domains of military, medical, industrial, agriculture and environmental monitoring.

Development and application profound influence will be generated to every domain of human-being.

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PurposePurpose

Advantages of Telosb nodeLow cost.Low power consumption.Small size.The structure of wireless sensor network directly

affects system performance.

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Methods & Methods & MaterialsMaterials Architecture

Hardware

○ Self-organizing and multi-hop network.

○ A large numbers of sensor nodes.

○ Monitor the information comprehensively and in time.

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Specifcation of Crossbow’s TelosB mote

IEEE 802.15.4 compliant 250 kbps, high data rate radio TI MSP430 microcontroller with 10kB RAM Integrated onboard antenna Data collection and programming via USB interface Open-source operating system

Methods & Methods & MaterialsMaterials

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Methods & Methods & MaterialsMaterials

TelosbTwo major goals: ○ Easy to use○ Minimal power consumption(sleep quickly)

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Methods & Methods & MaterialsMaterials

The composition of the nodeSensor moduleProcessor moduleRadio moduleEnergy supply module

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Methods & Methods & MaterialsMaterials

Distributed nodes

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Methods & Methods & MaterialsMaterials

The characteristics of node

Since wireless sensor nodes are used to monitor.

The node cost and energy supplies seem worthy of consideration.

The transmission distance and the number of nodes must be balance.

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Methods & Methods & MaterialsMaterials Architecture

Software

○ Sleep and wakeup modes.

○ Concurrent tasks.

○ Programming interface and platforms.

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Methods & Methods & MaterialsMaterials

TinyOS A open-source lightweight operating system.

Specifically designed for low-power wireless sensors.

Implemented by NesC

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Methods & Methods & MaterialsMaterials

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Data Memory ModelSTATIC memory allocation!○ No function pointers

Global variables○ Available on a per-frame basis

Local variables○ Saved on the stack

Methods & Methods & MaterialsMaterials

NesCC dialect with features to reduce RAM and code size.

Programmers can define new components using a C - like syntax.

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Methods & Methods & MaterialsMaterials

Interfaces Two kinds of functions: ○ Commands ○ Events

Users can call commands.

Providers can signal events.

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Methods & Methods & MaterialsMaterials

Components Two types of components in nesC :○ Modules○ Configurations.

A NesC application consists of one or more components assembled, or wired, to form an application executable.

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Methods & Methods & MaterialsMaterials

Execution Model Interrupting tasks at any time.

A task posted are executed later.

A task a lightweight deferred procedure call.

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ConclusionsConclusions Analyzing wireless sensor node telosb and the

operating system TinyOS.

TinyOS is specifically designed for low-power wireless sensors

The telosb node with low cost, low power consumption and small size,

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Thank You For Your Attention

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