towards seamless navigation ari virtanen, sami koskinen vtt industrial systems p.o.box 1302, 33101...

Towards Seamless Navigation

Ari Virtanen, Sami KoskinenVTT Industrial Systems

P.O.Box 1302, 33101 Tampere

Finland

[email protected], [email protected]

VTT TECHNICAL RESEARCH CENTRE OF FINLAND

MobileVenue ‘04 Athens, Greece

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



Outdoor positioning

• GALILEO doubles number of satellites in

space and is designed for use in Europe

• 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

• Receiver sensitivity is increasing

• Power consumption is decreasing

• 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



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

• 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



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.

Typical LAN has too few base stations for triangulation

Large cell sizes for Cell ID

Lack of wlan enabled mobile phones

AP 1

AP 2

AP4

AP9

AP1

AP2 AP5

AP3 AP6

AP7

AP8

AP10



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



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

X

XX

X(X1,Y1)

(X2, Y2) (X3,Y3)

(X4,Y4)



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)



Positioning fusion

• Check availability• Read time, coordinates

and error estimate • Check validity

• Calculate vote kn:

1,

is velocity constant [ ],

is age of the fix [ ]

is error estimate [ ]

nage

ms

age

k wheret v

v

t s

m

max( )nk• Select

BluetoothWLANGSM/GPRS Serial port

GPS

DRM

DigianswerHCI

Ekahauclient

VTT wlan network

NMEAparser

VTTSinikoneBluetooth

nodes

RFComm

YAXparser

GPSposition

DRMparser

DRMposition

selection

Radiolinja

GSMposition

Ekahaupositioning

server

NOPPAserver

WLANposition

Bluetoothposition

Bluetoothpositioning

module

Positioningrequest

compasspedometer

selectionselection

selection

Nokia D211

Positioning "Agent"

VTT LANSnavigation and guidance

application

Position

Voting

HW

Drivers

LANS

RFID InfraRedLight



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.



Map creation• Owner or operator of the target produces• Easy-to-use tools• Multipurpose result

Filter

Floor plansGeometric model

Servicedescription

Routinginformation

CAD DRAWING

IFC MODEL

GIS

GMLGDF

Images

DWG

DXF

Links

Services

Local Area Document

<XML><Index><metadata>

<MAP> ... </ MAP> <services> <restaurant> <shop> ... </services>...

Creation

Editor

URLJPGSVG



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)



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.

towards seamless navigation ari virtanen, sami koskinen vtt industrial systems p.o.box 1302, 33101...

Documents

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indoor positioning methods

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tampere finland