Location Based services

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Benghazi-Libya

University of BenghaziFaculty of Information Technology

Computer Networks & Communications Department

LOCATION BASED SERVICES

AUTUMN 2012 / 2013

Name: Faraj Ramadan Kassem ID: 415

Supervisor : Dr. Adel Aneiba

Benefits to Community

Car Tracking Personal Navigation News M-Commerce EmergencyChild Tracking

M-commerce: Mobile Commerce

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Benefits to Community (Cont`d)Location Based Services

Maps & Navigation

Tracking Services

Information Services

Application

Maps Routing Assisted

Navigation

Friends & Family Finder

Traffic Vehicle

Tracking

City guides User

Generated Content (UGC)

Social Networks

Context Advertisements

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Aim and Objectives

Outlines

Introduction

Comparison of Positioning Systems

LBS Components

Positioning Systems

Conclusion and Future Work

Privacy of LBS

3/23

Aim and ObjectivesAim :• To evaluate a Location Based Services (LBS) positioning techniques.

Objectives:

To investigate the characteristic of the LBS.

Gaining an understanding of components of LBS and underlying technologies.

To study the existing LBS systems.

Investigating the challenge of protecting the privacy of LBS users

To comparing between the LBS systems.

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Services

Location + Requests

Services

Introduction

LBS Provider

LBS User

Location + Requests

LBS Application

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LBS as an intersection of technologies

Introduction (cont`d) 7/23

LBS Architecture :

LBS Components

Location Collection Service (LCS)

GIS ProviderLocation Tracking

GISData

LBS Middleware

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LBS Middleware Standards

LBS Components (Cont`d)

The Open Location Services (OpenLS) standard proposes

an overall system architecture for various components :

location collection services .

LBS application providers .

Geography Markup Language (GML): This is an XML-

based language for representing various geography data such as

points of interest.

Keyhole Markup Language (KML): This complements GML by

providing information about annotations and markings on maps

(visualization).

Three important standards (OpenLS, GML and KML)

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• Why privacy is a concern with LBS ?

• Identification Requirements of LBS .

Anonymous LBSs.

Identity-driven LBSs.

Pseudonym-driven LBSs.

• Privacy Solutions

Anonymization.

Cryptographic Techniques.

Transformation of Location request data.

Privacy in LBS10/23

Evaluation of LBS Positioning Systems

• Cell of Origin (COO): This technique is used if the positioning system has a cellular structure.

• Time of Arrival (TOA): Time Difference of Arrival (TDOA).

• Angle of Arrival (AOA): If we use antennas with direction characteristics.

Basic Location Techniques

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Triangulation:: needs two fixed positions (p1 and p2). , we measure the angle to the location u.

Trilateration:: also needs two fixed positions, but uses two distances to the unknown location.

Traversing: uses several distance–angle pairs. We start with a known point p1 and measure the bdistance and direction

Basic Location Techniques (Cont`d)

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Satellite Basede.g. GPS

Network BasedGSM

Indoor PositioningInfrared , RFID & WLAN

Positioning Systems

GPS (Global Positioning System ) WLAN (Wireless Local Area Network RFID (Radio Frequency Identification ) GSM (Global System for Mobile)

13/23Evaluation of LBS Positioning Systems(cont`d)

1. Satellite Based Positioning

• Cover huge geographical areas.• Standalone infrastructure and terminal-based

Advantages High accuracy World-wide coverage

Disadvantages Positioning requires line-of-sight between satellite and receiver High power consumption at the receiver High operation costs

Examples GPS (Global Positioning System) Galileo

Evaluation of LBS Positioning Systems(cont`d)14/23

Principle of satellite positioning.

1. Satellite Based Positioning (cont’d)

The user knows the distance of the satellite to him, as well as the position of the satellite r =c*∆t

So he can calculate a radius is somewhere on. But he does not know where on the radius he is.

By looking at the intersection of the coverage radius of at least 3 satellites, he can discover

his exact position

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2. Network Based Positioning (e.g. Cellular Positioning)

Focuses on positioning services within the coverage area of a cellular network.

• Advantages• Good yield (in most cases even indoors).• Some positioning methods require either no or only minor modifications at mobile

devices (firmware upgrade).

Disadvantages High signaling overhead. Moderate accuracy.

Examples Cell-Id. Enhanced Observed Time Difference (E-OTD). Assisted GPS (A-GPS).

Evaluation of LBS Positioning Systems(cont`d) 16/23

Evaluation of LBS Positioning Systems(cont`d)3. Indoor Positioning (e.g. WLAN Positioning)

Deployment in buildings, university campuses, and company premises Stand-alone and integrated infrastructures (e.g., RFID vs. WLAN)

AdvantagesLow power consumptionHigh accuracy

DisadvantagesProprietary systems, i.e., no standardization

Examples

WLAN positioningUltrasound positioningRFID positioning

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Evaluation of LBS Positioning Systems(cont`d)

Position can be detected by measuring Signal Strength of all wireless LAN access

points.

Wi-Fi: Wireless Fidelity

3. Indoor Positioning (e.g. WLAN Positioning)

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3. Indoor Positioning (cont’d)(Infrared , Ultra Sound , Video and RFID)

Infrared(Active Badge)

Ultrasound Video RFID

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Precision Medium Mechanism Tracking/Positioning

Category Name

25 m Radio TOA Positioning Satellite GPS

Depends on Cell Density 40-400

Radio COO, AOA, TOA

Both Network GSM E-

OTD

Dependent on Wi-Fi AP density 3 m

Radio Signal Strength

Positioning Indoor Wi-Fi

Cell Radio COO Tracking Indoor RFID

Comparison of positioning Systems 20/23

Conclusion and Future Work

Many LBS applications use GPS to determine the current location.

however: It only works outdoors because the receiver must have a direct view

to at least four GPS satellites.

no positioning system is accessible everywhere.

If a service wants to have high coverage, it has to rely on several positioning

techniques.

Conclusion:

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More investigations are required to assess the behavior of the LBS under

different positioning techniques.

To explore the limitations of the LBS paradigm .

To develop real LBS systems which are more intelligent and accurate.

More investigations are required to assess user experiences in regard to

privacy and security.

Conclusion and Future Work (cont`d)Future Work:

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[9] K. Dueker and J. A. Butler. "GIS-T Enterprise Data Model with Suggested Implementation Choices," Journal of the

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Any questions?Thank you