Towards Seamless Navigation
Ari Virtanen, Sami Koskinen
VTT Industrial Systems
P.O.Box 1302, 33101 Tampere
Finland
[email protected], [email protected]
VTT TECHNICAL RESEARCH CENTRE OF FINLAND
Introduction
• Seamless transition between navigation modes and services for example
from car mode  pedestrian mode  indoor mode
• Switching between positioning systems
• Switching between navigation applications
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Outdoor positioning
• GALILEO doubles number of satellites in
• Receiver sensitivity is increasing
space and is designed for use in Europe
• Power consumption is decreasing
• GPS future improvements like
transmission power increase
• Assistive technologies will improve
availability (AGPS, Pseudolites)
• E911 regulation drives integration of GPS
receivers into a cell phones
• Receivers become smaller and cheaper
• Navigation applications will have
more potential customers
• Fast Time To First Fix -time is
essential in pedestrian applications
• Patch antennas are not very suitable
for pedestrian GPS receivers
If satellite positioning become available indoors interest for other indoor
positioning methods will decrease
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Indoor positioning
• Several technologies is proposed,
accuracies vary from millimeters to
tens of meters
• Positioning technology need
infrastructure investments, which
must be profitable
• Technologies that can offer other
functions than positioning, such as
data transfer, are the most
potential candidates
• Wireless lan and Bluetooth fulfil
this requirement
• Cell phone positioning is too
coarse at even outdoor navigation
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• Other problems
• lack of suitable terminals
• lack of positioning method
standardisation
• complicated establishment of
connection
• detection of the presence of the
positioning service in unknown
environment
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Wireless LAN positioning
 Positioning based on signal strenghts
(RSSI) and triangulation or Cell ID
 Standard RSSI API and normalized
RSSI values needed for compatibility
reasons for wlan cards
 Positioning engine is manufacturer
specific  company specific code is
needed in the terminal.
AP 2
AP 1
AP10
 Typical LAN has too few base stations
for triangulation
AP3
 Large cell sizes for Cell ID
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AP8
AP4
AP1
 Lack of wlan enabled mobile phones
AP9
AP6
AP2
AP5
AP7
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Bluetooth positioning
• Lot of Bluetooth enabled cell phones on the market
• Connection to auxiliary positioning devices like GPS, compass or
pedometer
• Local Positioning (LP) profile deals data exchange protocol, not
positioning system architecture
• LP profile propose that terminal side take the initiative of
connection for the privacy reasons.
• Continuous inquiring consumes lot of power
• Long connection time (n*1.2 s inquiry period + connection time)
• RSSI is not distance correlated, triangulation is difficult
• Coordinates received form another Bluetooth device may be
incorrect or outdated
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Seamless positioning
• Selection of the best available positioning
information
• Comparison requires same datum and
error model
• Heuristic assumption that the mean of the
coordinates is not the best solution
• In practise situations where more than
two positioning results is available is
theoretical
• GPS - wlan or GPS - Bluetooth
• Application independent positioning API
needed at operating system level
• Geocoding requires databases
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(X2, Y2) (X3,Y3)
X
X
X
(X1,Y1)
X (X4,Y4)
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Positioning demo implementation
• Hardware
• Compaq iPaq
• Digianswer Bluetooth card
• Nokia D211 wlan/gprs card
• Positioning systems
• Garmin XL12 GPS receiver
• Bluetooth positioning (VTT)
• Wlan positioning (Ekahau)
• GSM positioning (Radiolinja)
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Positioning fusion
VTT LANS
navigation and guidance
application
• Check availability
• Read time, coordinates
and error estimate
• Check validity
• Calculate vote kn:
kn 
tage
Positioning "Agent"
Position
Voting
GSM
position
WLAN
position
Positioning
request
1
,where
v 
YAX
parser
Bluetooth
positioning
module
GPS
DRM
position position
DRM
parser
NMEA
parser
LANS
selection
Ekahau
client
RFComm
v is velocity constant [ ms ],
Nokia D211
Digianswer
HCI
Drivers
HW
selection
tage is age of the fix [s ]
GSM/GPRS
WLAN
 is error estimate [m]
Bluetooth
selection
Serial port
selection
DRM
compass
pedometer
VTT wlan network
• Select max(kn )
Radiolinja
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Bluetooth
position
NOPPA
server
Ekahau
positioning
server
VTT
Sinikone
Bluetooth
nodes
GPS
RFID
InfraR
Ligh
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Local area maps
• Areas with dynamic information,
more details and smaller map scale
• Densely built outdoor areas: city
centers, exhibition grounds,
amusement parks ...
• Indoors: Commercial centers,
airports, train stations, museums ...
• Navigation and guidance, search for
area/building service database
• Targeted for mobile users; use in
personal navigation, fire and rescue
services, industry, maintenance,
guarding, cleaning etc.
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Map creation
• Owner or operator of the target produces
• Easy-to-use tools
• Multipurpose result
Creation
Routing
information
Services
Local Area
Document
Serv ice
description
<XML>
<Index>
<m etadata>
CAD DRAWING
IFC MODEL
DWG
<MAP>
...
</ MAP>
<s ervices >
<restaurant>
<s hop>
...
</services>
Editor
Filter
DXF
Floor plans
Geometric model
GML
GDF
GIS
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JPG
SVG
Images
URL
Links
...
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Map distribution and usage
• Distributed creation, distributed
delivery
• Specialised map servers
• Part of the target www-pages
• Search by location name, address,
coordinates or particular service
• Application is responsible for user
interface
• Different user groups need
different information (general
public, special groups,
maintenance, rescue)
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Conclusions
• Seamless navigation is possible, but several problems need to be solved
• Local area map standardisation, creation and distribution methods
• Indoor positioning development towards GPS usability: standardisation,
methods and service detection.
• Indoor positioning should be based on technologies which have data
transfer as primary function for financial reasons.
• If satellite positioning become available indoors, it replaces the other
indoor positioning technologies.
• Positioning and network connection interdependence must taken account
when indoor navigation service is designed.
• Datum and error models are very important
• Geocoding is matter of navigation application, not the positioning system.
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