1. Mapping the GSM landscape SVG Open 2005

2. Goal Location determination –Best effort –Automatic Take whatever is available: –GPS Accurate, but requires hardware and has limited battery life –Wifi / Bluetooth Cheap, but ad hoc –Mobile networks (operator based) No extra hardware, but operator dependency and expensive –Mobile networks (central registry) Operator independent and cheap, but limited coverage.

3. Cell-id database Central data source with cell information –Converts cell-id into location –Based on multiple measurements –All automatic GPS measurements –Free to use, but expect new cells in return –User is also contributor –Easy access via web services –Focus area: western Europe Alternatives: –cellspotting.com –placelab.org

4. July 2005 statistics 10389 cells of 35 operators, 264051 measurements in 14 countries, 57 provinces, and 229 postal code regions And growing every day…

5. Possible applications The well-known Friend Finder –Add location information to instant messaging –Like MSN adds the now-playing-track from MediaPlayer to the contact/buddy details Speech recognition of street and city names –Limit the degrees of freedom in the solution space Voice gateway –Call a fixed number to get information about items in your vicinity (attractions, ATMs, toilets, history,…) Bad connection marker –Predict bandwidth drops in advance for streaming application

6. Searching for a new home With one click an overview of all homes in the vicinity Without GPS but based on GSM cell location Integrated with Funda.nl

7. Where are my friends and colleagues? Exchange context information with relations Reason with context information Frequently visited places Predict destination Business travelling In a meeting In or out the office Demo!

8. An impression…

9. If you want to use the cell-id database An easy 4-step process: Get an impression of what is there: http://www.lab.telin.nl/~koolwaaij/showcase/gsmcells http://www.lab.telin.nl/~koolwaaij/showcase/gsmcells Sign a license and get the credentials from: koolwaaij@telin.nl koolwaaij@telin.nl Access the webservice to convert cell-id into lat-long: http://client140.lab.telin.nl:8080/wasp/services/CellStoreService?wsdl http://client140.lab.telin.nl:8080/wasp/services/CellStoreService?wsdl Generate the client stubs and use them in your application, use standard HTTP authentication

10. Code sample in C# Create a new project Add a web reference to the cell store service Call the web service: CellStoreService myService = new CellStoreService(); myService.Url = "http://server.nl/service"; myService.listCells(204,8,false); Returns a CellData[] with all cells for operator 8 (KPN) in country 204 (The Netherlands). It is as easy as that!

11. Thank you! http://www.telin.nl Johan Koolwaaij koolwaaij@telin.nl August 2005