This document discusses location-based services (LBS) and evaluates different positioning techniques used in LBS. It begins by introducing common LBS applications and services. It then examines the components and architecture of LBS systems, including LBS middleware and location tracking. Privacy concerns with LBS are also addressed. The document evaluates and compares several positioning systems used in LBS, including satellite-based GPS, network-based methods like GSM, and indoor positioning techniques. It concludes by discussing limitations and opportunities for future work improving LBS positioning accuracy and privacy.

1. `

2.  Car Tracking
 Personal Navigation
 News
 M-Commerce
 Emergency
 Child Tracking
M-commerce: Mobile Commerce

3. Location Based Services



Maps
Routing
Assisted
Navigation
Information
Services
Tracking
Services
Maps &
Navigation



Friends & Family
Finder
Traffic
Vehicle Tracking


City guides
User Generated
Content (UGC)
Application


Social Networks
Context
Advertisements

4. Aim and Objectives
Introduction
LBS Components
Privacy of LBS
Positioning Systems
Comparison of Positioning Systems
Conclusion and Future Work

5. • To evaluate a Location Based Services (LBS) positioning techniques.
 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.

6. Location +
Requests
LBS Provider
Location +
Requests
Services
LBS
Application
Services
LBS User

8. LBS Middleware
Location Tracking
GIS Provider
GIS
Data
Location Collection
Service (LCS)

9. Three important standards (OpenLS, GML and KML)
 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).

10. •
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.

11. • 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.

12.  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

13. Positioning Systems
Satellite Based
e.g. GPS
Network Based
GSM
(Global Positioning System )
(Radio Frequency Identification )
Indoor Positioning
Infrared , RFID & WLAN
(Wireless Local Area Network
(Global System for Mobile)

14. • 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

15. Principle of satellite positioning.
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

16. 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).

17.  Deployment in buildings, university campuses, and company premises
 Stand-alone and integrated infrastructures (e.g., RFID vs. WLAN)
 Advantages
Low power consumption
High accuracy
 Disadvantages
Proprietary systems, i.e., no standardization
 Examples
WLAN positioning
Ultrasound positioning
RFID positioning

18.  Position can be detected by measuring Signal Strength of all wireless LAN access
points.
Wi-Fi: Wireless Fidelity

19. Infrared
(Active Badge)
Ultrasound
Video
RFID

20. Name Category
GPS
Satellite
GSM
Network
Tracking/
Positioning
Positioning
Both
E-OTD
Wi-Fi
Indoor
Positioning
RFID
Indoor
Tracking
Mechanism
TOA
Medium
Radio
Precision
25 m
COO, AOA,
TOA
Radio
Depends on Cell
Density 40-400
Signal
Strength
Radio
Dependent on WiFi AP density 3 m
COO
Radio
Cell

21.  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.

22.  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.

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