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SULS

The Design Concept of a Simple Ubiquitous Learning System – SULS

一個簡易的無所不在學習系統 SULS 之設計概念

江振瑞 葉明貴 黃宇立

中央大學 資訊工程系

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SULS

Outline

IntroductionPreliminarySULS Application scenarioConclusion

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SULS

Outline

IntroductionPreliminarySULS Application scenarioConclusion

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SULS

Introduction(1/4)

The improvement of Wireless

communications and Micro

Electro-Mechanical Systems (MEMS) leads to an age of Ubiquitous Computing

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SULS

Introduction(2/4)

Learning Systems also step

from e-Learning, Mobile-Learning to Ubiquitous Learninging

With the help of the positioning ability

of learning devices and smart objects,

the ubiquitous learning system become context aware

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SULS

Introduction(3/4)

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SULS

Introduction(4/4)

A design concept, SULS – Simple

Ubiquitous Learning System, is proposed

here to support ubiquitous learning

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SULS

Outline

IntroductionPreliminarySULS Application scenarioConclusion

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SULS

Preliminary(1/7)

GPS (Global Positioning System)Line-of-sight between satellite and point nodesynchronous timer around three satellites

APS (Ad-hoc Positioning System)Not need LOS and synchronous timer

Based on DVRP(Distance Vector Routing Protocol) and the trilateration positioning technologyDV-Distance, one of the APS methods, is used in SULS

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SULS

Preliminary(2/7)

Anchor node

Anchor node

Broadcast it’s Position

Anchor nodeRSSI(received signal strength indicator)

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SULS

Preliminary(3/7)

Anchor node

Anchor node

Anchor node

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SULS

Preliminary(4/7)

RFID reader

DataClockEnergy

Contactless data carrier

= Transponder

Application

Coupling element(coil, microwave antenna)

RFID (radio frequency identity)Compose of reader, tag and application

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SULS

Preliminary(5/7)

RFID (radio frequency identity)Three kinds of tag

• Passive tag – no self battery– the simplest one

• semi-active tag • active tag

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SULS

Preliminary(6/7)

RFID reader

DataClockEnergy

Contactless data carrier

= Transponder

Application

Coupling element(coil, microwave antenna)

RFID (radio frequency identity)How passive tag works?

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SULS

Preliminary(7/7)

RFID(radio frequency identity)Working frequencies in the worldwide

• 135KHz • 13.5MHz• 433.92MHz• 860~930MHz(UHF)• 2.45GHz and 5.8GHz

The UHF tag can be read at a distance about 10m.

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SULS

Outline

IntroductionPreliminarySULS Application scenarioConclusion

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SULS

SULS(1/7)

SULSSimple Ubiquitous Learning System integratestwo existent technologies

APSRFID

three newly developed technologies

Farthest tag forwarding

Tag-assisted positioning

Multi-media data in-network cache

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SULS

SULS(2/7)

Farthest tag forwardingBack-off time = ((L-R)/L) x B

Where R:signal source distance

L:the farthest signal distance

B:the maximum back-off time

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SULS

SULS(3/7)

The farthest signal

distance250 m200 m

50 m

• The farthest signal distance= 250 m– Far away from 50m((250-50)/250)B=0.8B

– Far away from 200m ((250-200)/250B=0.2B

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SULS

GUIDE NODE:Node equipped with RFID reader

SULS(4/7)

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SULS

SULS(5/7)

Tag-assisted positioningAnchor node can be located by

• GPS

• Tags that have position information and are attached to smart objects

Other nodes can be located by three GUIDE NODEs

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SULS(6/7)

Multi-media data in-network

cacheGUIDE NODE has multi-media data of smart objects

Use cache to reduce network traffic and GUIDE NODE loading

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SULS

GUIDE NODE:Node equipped with RFID reader & multimedia library

SULS(7/7)

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SULS

Outline

IntroductionPreliminarySULS Application scenarioConclusion

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SULS

Application scenario

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SULS

Outline

IntroductionPreliminarySULS Application scenarioConclusion

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SULS

Conclusion

SULS a Simple Ubiquitous Learning System

a low cost and efficient Ubiquitous Learning system

use • simple devices

– Learning devices with mobile ability

– Few have RFID readers (plus GPS)

• three newly developed technologies– Farthest tag forwarding

– Tag-assisted positioning

– Multi-media data in-network cache

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SULS

Thanks for Your Listening!