Information Technology I
Special Topics
Location Based Services
陳秋男 P93747001
蔡政賢 P93747003
Agenda
Emergence of LBS
What is LBS?
Basic Use Cases
Location Service Concepts
Research Issues


Privacy
Interoperability and Standard
2
Technical Business Innovations
1876
1980
1995
1999
2000
Telephone
FAX
Internet
e-Everything
m – GIS and LBS
3
Convergence
The convergence of multiple technologies
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Internet
Wireless communication
Geographic information system
Location technologies
Mobile devices
4
Emerging mobile computing
application
Often need to know where things are physically
located.
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Location services, wireless location services, mobile
location-based services
Relating location to other pertinent information
gives meaning and value


We need directions from one place to another.
We want to interact naturally with I/O devices
available in our environment.
Allow that mobile users (MUs) use services
based in their position or geographic location
5
Emergence of Location Based
Services
Market Size
$10 Billion
Internet and Mobile
Location Services Market
$5 Billion
Inflection
Point
$1 Billion
GIS Market
1980
1990
2000
Time
2005
6
Nokia prognosis for 3G mobile
communication
Monthly income pr. user in euro (1 euro = 1 USD ca.)
100
Location based services
90
Div. telecomm.
80
Commercials
Text messages
Entertainment
70
Information services
Payment transactions
Music and video
Internet surfing
Download from internet
Chat on internet
Multimedia messages
Photo messages
60
50
40
Vide conferencing
30
20
Normal speech
10
Fixed subscription
fees
0
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
7
Agenda
Emergence of LBS
What is LBS?
Basic Use Cases
Location Service Concepts
Research Issues


Privacy
Interoperability and Standard
8
What is location-based service?
Definition 1 :

LBSs are information services accessible with mobile
devices through the mobile network and utilizing the
ability to make use of the location of the mobile
device. (Virrantaus et al. 2001)
Definition 2 :

A wireless-IP service that uses geographic
information to serve a mobile user. Any application
service that exploits the position of a mobile terminal.
(Open Geospatial Consortium (OGC, 2005))
9
What is location-based service?
A two way communication and interaction


User : tells the information he needs,
preferences and position
Provider : deliver information tailored to the
user needs
To answer :
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

Where am I ?
What is near by ?
How Can I go to ?
10
LBS as an intersection of
technologies
11
Basic Components
12
Agenda
Emergence of LBS
What is LBS?
Basic Use Cases
Location Service Concepts
Research Issues


Privacy
Interoperability and Standard
13
Basic uses of Cases
14
Agenda
Emergence of LBS
What is LBS?
Basic Use Cases
Location Service Concepts
Research Issues


Privacy
Interoperability and Standard
15
Location service concepts
The Device

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


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
Cell phone
Palm top
Lap-top
Kiosk
Car-based computer
Cell antenna
Mobile device
Display
Actors
16
Location service concepts
The Location

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Point and Reference
Segmented Line
Address
Route
Descriptive Directions
Gazetteer
Direction
Polygon
 Payload
Items
17
Location service concepts
The Service
–
–
–
–
–
–
–
–
Routing
Avoiding Traffic
Tourism
Regional Attractions
Event Handling
Maps and Backdrops
Guidance
Preference
 Service
Providers
18
Building Blocks of Location
Services
Basic Functions
Position
Distance
Route
Selection
Proximity
Description
Directory
Area
Distribution
Relationship
Suitability
Presentation
Inventory
Frequency
Pattern
Trend
Location
Servers
Demographics
Directories
Positions
Routes
Reports,
Maps
GraphicViews,
Messages
Sites
Assets
Events
Service Points
Transactions
19
Location Services System Concept
GPS
Location
(Application)
Service Client &
Positioning
SW/HW
OpenLS Interface Focus Areas
Mobile
Terminal
Location
App
Server
Location
App
Servers
GSM
Wireless - IP Platform
Internet
or
Intranet
(Core Network)
Gateway
Services
Network
Management
Network
Services
Mobile
Positioning
Server
Control
Location
Content
Servers
Database
Engine
20
Location Technologies
Network-based

Technologies that exploit the cellular infrastructure to
obtain geo-location information.
Handset-based

Location intelligence is stored within terminal
Each of these groups may be divided into:


The MU uses signal transmitted by the base stations
to calculate its own position
The base stations measure the signals transmitted by
the MU and relay them to a central site for
processing.
21
Location Technologies
network-based
CGI+TA (Cell Global Identity + Timing Advance)
X,Y
Cell Size
22
Location Technologies
network-based
UL-TOA (Uplink Time of Arrival)
Base Station 1
Mobile
T1 =distance 1
Base Station 3
Base Station 2
T2 =distance 2
T3
=distance 3
23
Location Technologies
network-based
AOA (Angle of Arrival)
1
2
24
Location Technologies
handset-based
GPS (Global Positioning System)
AGPS (Network Assisted GPS)
25
Location Technologies
handset-based
EOTD (Enhanced Observed Time Difference)
Difference 1-3
Base Station 1
Difference 1-2
Clock time 1
Mobile
Clock time 2
Base Station 3
Clock time 3
Base Station 2
Difference 2-3
26
Agenda
Emergence of LBS
What is LBS?
Basic Use Cases
Location Service Concepts
Research Issues


The complete LBS system
Interoperability and Standard
27
Research issues
Real-Time Location Information,


where is the nearest incident investigation site?
Where is the nearest hospital, restaurant?
Tracking,
Traffic Monitoring and Routing,
Telematics,
Real Time Bus Location Information
Systems.
28
Spatial Data
Essential component of LBS architecture

Storing and analyzing spatial data
Geographical Information System (GIS)

Refers to the computer-based capability to
manipulate geographic data
Maps or images can be stored in vector or
raster format.
A spatial object must have:
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Location: a known point
Form: a geometric representation
Attribute: the nature of the object
Spatial relationship: the boundary of an area
29
The Complete LBS System
Service
Gateway
WML
Mobile
Network
WML/HTML
SMS, GPRS,
Wireless Internet
AGPS
BS
AGPS
API
API
LBS Application
Server + Spatial
Functions
BS
API
Spatial Database
API
Billing Server
30
Traffic Information Services is NOT So
Simple
(You are about to join a ten kilometer traffic queue)
Create a planned route
Periodically get device location
Position device on appropriate transportation network
(usually streets)
 Route May be expressed as segmented line
expression
 Examine planned route for obstacles
Compute work-around if obstacle is discovered
Process and Present (portray) work-around
Obtain background road networks with street and place
names with scale and map up date as device moves
 Highlight planned route
 Highlight work-around route
31
Maneuver Examples
Turn onto street B
Bear to remain on street A
U-turn on street A
Turn to stay on highway A
Turn onto ramp B
Turn to enter a roundabout: pass n roads before
exiting
Entering a boat ferry
Turn to stay on street A (fork)
Stay straight through complex intersection
32
Advisory Examples
Approaching a toll booth
Exiting a tunnel
Entering a bridge
Entering a new country
Road name changes
Roads Merge
Approaching Intermediate WayPoint
Approaching Destination
Walk To Destination
33
Peak-hour Link
Time Table
Non Peak-hour
Link Time Table
Destination
4:30 PM
Origin
5:00 PM
4:00 PM
3:30 PM
34
Forecasting Spatio-Temporal Link Travel Time
35
Cost Functions for Routing and
Navigation
Find a route from my current position, stopping at
a gas station for 10 gallons of gas, a pharmacy
to pick up a bottle of Advil, and a flower shop
for a dozen roses before arriving home. Three
costs are involved:
(1) the purchasing and stopping costs,
(2) costs related to the time spent on the road,
and
(3) distance related costs such as gasoline used,
and the wear and tear from the use of a car.
36
Interoperability and standard
Life without standards
37
Kinds of standards- Four Types
By Level of
Coverage
International
Multinational, Regional
National
Local
By Level of
Prescriptiveness
Recommended Practice:
Advisory
Information Report:
Informative
Standard: Normative
By Function
Design Standards
Interface Standards
Framework Standards
Performance
Standards
Testing Methods
Terminology
By Development
Process
De facto
Regulatory
Consensus
38
A conceptual architecture for
LBS
Thin Client
or Appliance
Location
Service
Medium Client or Application
Appliance Specific Network
Catalog / Metadata Service
Service Registry
(Name Space Registry)
Proxy or Service Broker
System
Configuration
Services
Network
Geoparser
Service
Data Service
Navigation
Service
Gazeteer
Service
Web
Feature
Service
Geocoding
Service
Web Map
Service
Coordinate
Transformation
Service
Yellow
Pages
Service
Application (Geomatics) Services
Other Services
(as yet undefined)
39
Transferring geospatial Data
between different h/w & s/w
Geospatial data
S/W 2
Geospatial data
Standard
S/W 1
40
Summary
Several alternative location methods under
development

Sensor driven
Each application has its necessary accuracy
Achieving accurate location in urban areas is
challenging because of the effects of buildings
Standardization is focused on time-difference
methods and the use of GPS
41