2001 Prentice Hall, Inc. All rights reserved. 1 Chapter 3, Location-Identification Technologies and...

2001 Prentice Hall, Inc. All rights reserved.

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Chapter 3, Location-Identification Technologies and Location-Based Services

Outline3.1 Introduction3.2 Enhanced 911 Act (E911)3.3 Identifying Cellular Devices: Cell-ID3.4 Location-Identification Technologies

3.4.1 Cell of Origin (COO)3.4.2 Angle of Arrival (AOA)3.4.3 Time Difference of Arrival (TDOA)3.4.4 Enhanced Observed Time Difference (E-OTD)3.4.5 Location Pattern Matching3.4.6 Global Positioning System (GPS)3.4.7 Java and Location-Identification Technologies


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Chapter 3, Location-Identification Technologies and Location-Based Services

Outline3.5 Location-Based Services

3.5.1 Automotive 3.5.2 Fleet Tracking3.5.3 Location-Based Advertising and Marketing3.5.4 Agriculture and Environmental Protection3.5.5 Security and Theft Control3.5.6 Accessibility and Wireless Technology3.5.7 Wireless Mapping

3.6 Location Interoperability Forum3.7 Internet and World Wide Web Resources


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3.1 Introduction

• Telematics– Convergence of computer technology and mobile

telecommunications

– Location-based services (LBS): telematics application determines wireless user’s location


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3.2 Enhanced 911 Act (E911)

• E911 Act: Federal Trade Commission standardizes and enhances 911 service– Phase 1: carriers must provide Automatic Number

Information and cell site

– Phase 2: carriers must provide Automatic Local Identification

• Benefits– Pinpoint location when driver unsure or call breaks up

• Obstacles to providers– Standardization

– Infrastructure development


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3.3 Identifying Cellular Devices: Cell-ID

• Cell-ID: number identifies cellular device to network– Communications between device and tower

– Cloned phones: 2 phones share same ID (criminality)


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3.4 Location-Identification Technologies

• Determining Location– Carrier presents geocode (lattitude and longitude) to content

provider, translated into map

– Triangulation: uses angle from at least 2 fixed points

• Location-ID Technologies– Satellite-based: satellites determine location

– Network-based: cellular towers determine location

– Network-centric: device location managed by network, no device upgrade needed

– Handset-centric: device upgrade necessary to determine location


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• Obstacles– Cost: enhancements to handsets

– Standardization: E911 act

• Location-Identification Technologies– AccuCom

– TruePosition

– Cell-Loc

– Grayson Wireless

– Cell Trax

– KSI, Inc.

– Lockheed Sanders

– Snap Track


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• Location-Identification Technologies (Cont’d)– U.S. Wireless

– SigmaOne

– Cambridge Positioning Systems

– Corsair – Phonetrack

– Radix Technologies, Inc.

– Symmetricom

– Tendler Cellular

– Integrated Data Communications


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Technology Upgrade Degree of Accuracy

Cell of Origin (COO) No Least accurate of technologies discussed. User could be anywhere in tower’s range. Meets only Phase I of E911 Act.

Angle of Arrival (AOA)

No Fairly accurate. User is within the overlap of two towers’ cell sites. Used primarily in rural areas where there are fewer towers. Complies with Phase II of E911.

Time Difference of Arrival (TDOA)

No Accurate. User’s location is determined by triangulating from three locations. Complies with Phase II of E911. Most effective when towers are close together.

Enhanced Observed Time Difference (E-OTD)

Yes Accurate. User’s location is determined by triangulating from three locations. Complies with Phase II of E911.

Location Pattern Matching

No upgrade to device or network, but database must be maintained.

Accurate. User’s location is determined by matching noise and interference in a given area, making it more effective for locating a device in an urban area.

Global Positioning Systems (GPS)

Yes Highly accurate. A user’s location can be determined anywhere on earth. However, GPS is not as effective when the user is indoors.

Fig. 3.1 Location-identification technologies.


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3.4.1 Cell of Origin

• Cell of Origin: most primitive method– COO = area covered by specific tower

– No way to determine caller’s position within cell

Cell-pho ne user canbe anywhere withinthe to wer’s range.


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3.4.2 Angle of Arrival

• Determines position based on angles from cell phone to two or more towers– AOA equipment determines longitude and latitude by

triangulation

• Interference in urban areas– AOA works best in sparsely populated areas

• AOA combined with TDOA provides highly accurate service


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3.4.2 Angle of Arrival

AOA technology in action(Courtesy of Dispatch Monthly Magazine)


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3.4.3 Time Difference of Arrival (TDOA)

• Time Difference of Arrival– Determines distance using triagulation from signal’s travel

time

– Location determined from intersection of distance arcs

• Cell-Loc, TimesThree, and TDOA– Cell-Loc: developing wireless information portals

• Created Location XML

• Uses TDOA

• TimesThree division of Cell-Loc: make location-based services widely available


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3.4.3 Time Difference of Arrival (TDOA)

Illustration demonstrating TDOA (Courtesy of National Communications System)


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3.4.4 Enhanced Observed Time Difference (E-OTD)

• Enhanced Observed Time Difference– Location determined from signal travel time to 3 towers (like

TDOA)

– Towers initiate transmission to handset

• Obstacles– Handset upgrades

– Dependence on GSM standard, not widely used in US


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3.4.4 Enhanced Observed Time Difference (E-OTD)

© ETSI [date]. Further use, modification, redistribution is strictly prohibited. ETSI standards are available from [email protected]<mailto:[email protected]>, and <http://www.etsi.org/eds/eds.htm>


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3.4.5 Location-Pattern Matching

• Multipath– Multiple routes for energy beam

– Interference from multipath deflecting off buildings

• Location-pattern matching– Locations defined by multipath characteristics and stored in

database

– Not effective in rural areas


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3.4.5 Location-Pattern Matching

Location-Pattern Matching (Courtesy of U.S. Wireless Corporation. All rights reserved.)


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3.4.6 Global Positioning System (GPS)

• Global Positioning System: satellites track position– Standard Positioning Service: 100 meter accuracy

– Precise Positioning Service: 10 meter accuracy, originally only for military

– Random-error signal: scrambling mechanism, prevent foreign powers’ use of service

• GPS’ 24 satellites on fixed orbits– Satellite sends signal and measures distance

– User’s position determined by intersection of 3 distance spheres


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3.4.6 Global Positioning System (GPS)

• GPS Disadvantages– Costly

– Signals lose strength over long distance


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3.4.7 Java and Location-Identification Technologies

• Many location-based services use Java– Java used to design intelligent agent software: retrieve data

from database

– Java specification Jini: improve portability across dissimilar aplliances

– Java Location Services

• Object FX– C-it Locate product created entirely with Java

• Java is flexible– Can be changed and modified to support future technology

developments


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3.5 Location-Based Services

• Locating and providing users with information• Raises privacy concerns• Regulation issues


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3.5.1 Automotive

• Location-based services available in automobiles• Motorola OnStar system

– Security and reliability

– Route support, vehicle diagnostics, and medical assistance

• Ford ATX Wingcast– Telematics services

• Traffic Monitoring– Traffic patterns based on # of mobile devices in traffic


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3.5.2 Fleet Tracking

• Trucking companies use location-based services to minimize cost and maximize productivity

• Terion Corp.– GPS device on LCD screen for mapping and communication

• Cimarron Technologies– Monitors location, speed, direction

– Helpful for dispatching taxis

• Army Movement Tracking System– Tracks location of vehicles and weapons


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3.5.3 Location-Based Advertising and Marketing

• Discounts and promotions transmitted when store/restaurant is in proximity

• Permission-based marketing and advertising– Lucent Technologies

– Profilium, Inc.

– Go2 Systems

• Motorola– Virtual Advisor: alerts drivers preset specified locations


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3.5.4 Agriculture and Environmental Protection

• Planting and Harvesting– GPS technologies map lands, estimate yields, and develop

harvesting strategies

• Forestry and Conservation– Regulate planting, map deforestation, protect wildlife

• Fishing– Maps fishing areas and vessel locations


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3.5.5 Security and Theft Control

• Location devices used to track stolen items– LoJack Stolen Vehicle Recovery Network

• Track movements of paroled criminals


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3.5.6 Accessibility and Wireless Technology

• Location-based services aid people with disabilities in navigation, emergency services, and communication

• Digital Angel– Locates and analyzes vital signs of lost and distressed


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3.5.6 Accessibility and Wireless Technology

Digital Angel Accessibility Products (Courtesy of Digital Angel™ Corporation)


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3.5.7 Wireless Mapping

• Map access on wireless devices– Maps, landmark info, distance measurements

– Geodiscovery

– Mapquest


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3.6 Location-Interoperability Forum

• Location-Interoperability Forum– 70 member organization

– Standardization of wireless technologies

– Access to location information

2001 Prentice Hall, Inc. All rights reserved. 1 Chapter 3, Location-Identification Technologies and...

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