Introduction to LBS

Fall 2004CS644

Advanced Topics in Networking

Sue B. MoonDivision of Computer Science

Dept. of EECSKAIST

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Location Based Services

• Services that integrate a mobile device's location or position with other information so as to provide added value to a user

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Taxonomy

• Person-oriented– e.g. friend finder– M-commerce

• Device-oriented– e.g. car tracking for theft recovery

• Push services– e.g. subscription-based service

• Pull services– e.g. where to find the nearest cinema?

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Location Determination Technologies

• Network-based– Cell-ID trace mechanism

• 단점 :– Accuracy: up to 2km urban, 30km rural

– CI-TA (Cell-ID with Time Advance)• Calculate delay between handset and base station

– AOA (Angle of Arrival)• Use multiple antennas at base station• Triangulation of location based on angles of signal

reception

– TDOA (Time Difference Of Arrival)• Exploit relative difference between two base stations

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Location Determination Technologies

• Handset-based– GPS (Global Positioning System)

• Need a view of 3 satellites out of 24 of US Gov't• 단점 :

– Long Time-to-First-Fix (TTFF)

• Hybrid– GPS-DR (Dead reckoning)– Wireless-Assisted GPS (WAG)

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General LBS Comm Model

GIS

Application

Middleware Layer

Positioning Layer

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OSFi (Open Srouce Gateway Initiative)Java-based S/W Architecture

Application

OSGi Core and Optional ServicesDevice Mgr, HTTP service, User Admin, etc.

Hardward Platform

S/W PlatformReal-Time OS

Network DriversTCP/IP, 802, Bluetooth, etc.

Native CodeVR, TTS

Application Application

OSGi FrameworkCore APIs for applications to share JavaVM:

life cycle mgmt, security,

Java 2 Micro Edition (JVM)

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AMI-C(Automotive Multimedia Interface Collaboration)

Standard Platform API

Middleware

OS

Hardware

Car Navitaion Contents Internet Theft Prevention

AudioOther Device

S/W Platform Standard

H/W Platform Standard

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Telematics

• Telematics = telecommunication + informatics

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References

• "Location-Based Services" by Jochen Schiller and Agnes Voisard, Morgan Kaufmann

• 텔레매틱스 개론 by 송준화 외 다수 , 홍릉과학출판사