Molde University College INF 245 Fall 2007 OBø 1 INF245 Mobile applications Location Based Services H 2007 Ola Bø

Molde University College INF 245 Fall 2007 OBø 2 Location based services Introduction Uses information about the users position to deliver a service Valuable for the mobile user Possible services Emergency services Finding the route Advertise local events and services Driving force USA – FCC requires an improved 911-service Europe E-112 Europe and Asia m-commerce What if the service will be used somewhere else than current position 1. generation: The user registers position information himself – postal code or city/street Position-dependent content: driving directions, restaurants, shops, weather 2. generation: Can find position with no user assistance. – low accuracy Similar to 1. generation 3. generation: Accurate positioning with no user assistance Starting services, updated information from nearby shops and detailed maps, fleet mgmt.

Molde University College INF 245 Fall 2007 OBø 3 The E911-service 911 is the US emergency number FCC requires positioning of emergency calls Position as important as type of emergency Phase 1: done What tower received the call and caller’s number Phase 2: to be completed by :difficult Positioning accuracy 124 m in 67 % of the cases should be 95 % finished by 2005 Consequences Accurate positioning of mobile phones available in the US Many possible applications – will they become reality – Cost, Privacy legislation Similar initiative in Europe: E112

Molde University College INF 245 Fall 2007 OBø 4 Applications using positioning information Emergency services Traffic information Navigation Service personnel management Fleet management Tracking Packages Cars Wireless advertising Finding services Map services Weather information

Molde University College INF 245 Fall 2007 OBø 5 Mobile positioning techniques Accuracy vs. cost Network based solutions Cost effective, but inaccurate ~1000 m Works for all handsets Handset based solutions More expensive and more accurate ~10 m Mixed solutions

Molde University College INF 245 Fall 2007 OBø 6 Network based positioning Cell identity The cell is identified But where is the user in the cell? Accuracy ~1 km Dependent upon cell size Unusable for many purposes Can be improved Cell divided into sectors Distance from tower measured in Timing Advance Combined method: Cell global Identity-Timing Advance (CGI- TA) Accuracy ~100m Applications get information from MPC (Mobile Positioning Center) Higher accuracy in cities than in the countryside – Why?

Molde University College INF 245 Fall 2007 OBø 7 Network based positioning Time of Arrival Uses information from three or more base stations Time for arrival of signal from phone to base stations is measured Base stations with accurate and synchronous clocks (expensive) Distance from phone to base stations is measured With three or more base stations position can be accurately determined No handset modification necessary Accuracy ~50 m 30m/ m/s=0, s maximum deviation between base station clocks

Molde University College INF 245 Fall 2007 OBø 8 Hand set based positioning Enhanced Observed Time Difference (E- OTD) Same solution as for Time of Arrival, but on the handset The base station sends accurate and synchronized clock signals Time difference is measured Position is calculated in handset or by network Requires special handsets

Molde University College INF 245 Fall 2007 OBø 9 More possibilities for network/handset- based positioning Signal strength Relative time difference supported by a database for the area

Molde University College INF 245 Fall 2007 OBø 10 Handset based positioning GPS Global positioning system 24 satellites in orbit Limitations requires free sight to at least 3 satellites trees and buildings block No GPS inside buildings But up to the building entrance Heavy calculations Takes time to find first position (20-40s)

Molde University College INF 245 Fall 2007 OBø 11 Handset based positioning GPS GPS as a separate unit Now starting to be embedded Falling prices, augmenting use One Way communication from satellite Built upon triangulation Accurate ~10 m improved using D-GPS Can be combined with other positioning services Assisted GPS (A-GPS) Calculations performed on server Satellite information already collected – quicker positioning Differential GPS solutions can improve accuracy to 10 cm

Molde University College INF 245 Fall 2007 OBø 12 Data stream from a GPS $GPRMC, ,A, ,N, ,E,0.12,67.71,041104,,*3C $GPGGA, , ,N, ,E,1,04,3.2,92.9,M,42.7,M,0.0,0000*45 $GPGSA,A,3,05,09,30,04,,,,,,,,,4.6,3.2,3.3*3A $GPRMC, ,A, ,N, ,E,0.14,136.60,041104,,*05 $GPGGA, , ,N, ,E,1,04,3.2,92.4,M,42.7,M,0.0,0000*46 $GPGSA,A,3,05,09,30,04,,,,,,,,,4.6,3.2,3.3*3A $GPRMC, ,A, ,N, ,E,0.11,144.76,041104,,*0C $GPGGA, , ,N, ,E,1,04,3.2,92.9,M,42.7,M,0.0,0000*49 $GPGSA,A,3,05,09,30,04,,,,,,,,,4.6,3.2,3.3*3A $GPRMC, ,A, ,N, ,E,0.15,143.11,041104,,*0C $GPGGA, , ,N, ,E,1,04,3.2,93.6,M,42.7,M,0.0,0000*42 $GPGSA,A,3,05,09,30,04,,,,,,,,,4.6,3.2,3.3*3A $GPRMC, ,A, ,N, ,E,0.18,149.46,041104,,*0C $GPGGA, , ,N, ,E,1,04,3.2,93.5,M,42.7,M,0.0,0000*4D $GPGSA,A,3,05,09,30,04,,,,,,,,,4.6,3.2,3.3*3A $GPGSV,3,1,10,05,71,213,41,09,47,144,36,14,44,281,00,30,40,242,40*7B $GPGSV,3,2,10,07,22,048,00,04,19,086,28,01,13,330,00,20,09,010,00*73 $GPGSV,3,3,10,31,08,040,00,24,05,117,00*72 Sentence GGA Function: Global Positioning Fix Data Example: $GPGGA,120757, ,N, ,W,1,06,2.5,121.9,M,49.4,M,,*52 Synopsis: time of fix (hhmmss), latitude, N/S, longitude, E/W, Fix quality (0=invalid, 1=GPS fix, 2=DGPS fix), number of satellites being tracked, horizontal dilution of position, altitude above sea level, M (meters), height of geoid (mean sea level) above WGS84 ellipsoid, time in seconds since last DGPS update, DGPS station ID number, checksum fra

Molde University College INF 245 Fall 2007 OBø 13 EGNOS European Geostationary Navigation Overlay Service Satellite based augmentation system Supplements the GPS and Galileo* positioning system reporting their errors to improve accuracy Started July m accuracy, 99% availability Certified for life critical applications from 2008 *Galileo is an European parallel to the GPS system to be completed by 2011.

Molde University College INF 245 Fall 2007 OBø 14 Proximity based positioning If you are connected you are there! Built upon short range technology RFID BT WLAN (proprietary solutions to identify the base station being used)

Molde University College INF 245 Fall 2007 OBø 15 Telenor’s positioning product

Molde University College INF 245 Fall 2007 OBø 16 Geographic Information Systems GIS Coordinates is not enough GIS gives position information a context GIS can contain a wealth of information What is where Patterns Applications What is near by m-commerce Driving directions Emergency messages In Norway GAB (Grunneiendommer, Adresser og Bygningsmasse) is a developed GIS GIS a study in it’s own right!

Molde University College INF 245 Fall 2007 OBø 17 Geographic information systems Demonstration and Discussion Demonstration Norgesglasset Visveg Gule sider Finn Mappoint Drøfting What generation of LBS do the presented services represent How can the services exploit position information Can the services be interesting in a mobile context as well What must be changed to permit mobile use of the services?

Molde University College INF 245 Fall 2007 OBø 18 Development of location based services A Market in development A Complex situation Proprietary API for access Network based API  Mobile Positioning Center MPC Hand set based API Standardization Location Interoperability Forum under OMA Open Gis Consortium ISO/TC211

Molde University College INF 245 Fall 2007 OBø 19 Other solutions Ugland IT Statkart