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6 th IT Excellence Awards (Post Secondary). Mobile Application Generator for Route-based Location Sensitive Tourist Companion using Change of GSM Cell ID Event. 2004/06/09. Lee Kwok Chau, Tommy (leekc1@cse.cuhk.edu.hk) V ideo over I ntern E t and W ireless Technologies Lab ., CUHK.
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6th IT Excellence Awards(Post Secondary) Mobile Application Generator for Route-based Location Sensitive Tourist Companion usingChange of GSM Cell ID Event 2004/06/09 Lee Kwok Chau, Tommy (leekc1@cse.cuhk.edu.hk) Video over InternEt and Wireless Technologies Lab., CUHK
Agenda • Traditional Mobile Tourist Directory Solutions • Location Estimation Using GSM Cell ID • Tools for Fast Generation of Tourist Companion Software • Sample Applications: MTR Travaller, CU Campus Bus
Location-Based Services (LBS) • Services are provided based on user’s current location. • Applicable on different fields: • Navigation (e.g. Driving) • Shopping / Tourist Guides • Games / Entertainment, …… • Location estimation acts as a mobile tourist directory solution where information and interaction are triggered by tourists’ current locations.
Current Technologies on LBS • 1) Global Positioning System (GPS) • Good Accuracy: 30-100m • Poor indoor and urban-area capabilities • Generally high power consumption • Expensive hardware at end users • 2) 3rd Generation GSM (3G) • 2G-compatible network – the majority • Extra investment in addition to existing 3G network • 3) Modified SIM Card • Require telco support • 4) Existing GSM Network • Fairly advanced • Expensive and require run-time support from telco
GSM Positioning Methods • TOA (200m - 10km) • E-OTD (50m - 100m) • AOA (>>150m) • A-GPS (10m - 50m)
Motivation • Current positioning methods require: • extra cost to existing network / synchronization between base stations • special hardware to end users • telco-dependent • Tourist companion software does not require very accurate location information • GSM cell information (e.g. cell ID) is available in ordinary GSM handset • Symbian phone offers programming capability for general developers • Location estimation by GSM cell ID is adopted in our project
Overview of GSM Cell ID Location Estimation • Each base station has unique location ID and cell ID pair • Main idea: each base station can somehow provide certain ‘information’ about a particular location Location ID: [50] Cell ID: [2] Location ID: [50] Cell ID: [3] Location ID: [50] Cell ID: [4] Location ID: [50] Cell ID: [1]
Overview of GSM Cell ID Location Estimation • Advantages: • Simple implementation – passively obtaining current registered cell ID • Applicable on ordinary GSM phones • Without any support from telco
Experimental Results For Peoples
Experimental Results For SmarTone
Conclusion of the Experiment • Potential difficulties/inaccuracies in 2D Space • Cell sizes are varying • Extent of cell overlapping is quite large • Reliability greatly depends on the deployment and configuration of cells by network operators • A more robust approach is required • Making use of GSM cell change events • Applying on 1D path (for route-based LBS)
GSM Cell Change Event • Received signal strength from current registered cell is weaker than another, so cell change occurs • Consequences: • More information provided • More reliable in detecting boundary
Location: [50] Cell ID: [2] Location: [50] Cell ID: [4] Location: [50] Cell ID: [3] Location: [50] Cell ID: [1] Cell ID: [1->2] Cell ID: [2->3] Using GSM Cell IDs in 1D Space • A set of multiple cell change events can indicate a path
MTR Cell ID Data • Peoples
MTR Cell ID Data • SmarTone
MTR Cell ID Data • Sunday
KCR Cell ID Data • Peoples
KCR Cell ID Data • SmarTone
Advantages of New Approach • Allow to keep track of entering and leaving a region • Become more reliable than purely mapping cell ID to location • Get rid of the problem of inconsistent cell sizes and high extent of cell overlapping • 30-300m accuracy, enough for route-based mobile tourist companion software
GSM Cell Change Method(Boundary / Line Based) GSM Cell Change Method in 1D Path(Point Based) Pure GSM Cell Information Location Estimation(Region Based) Detect registered cell change occurred at cell boundary Concentrate on specific cell changes (intersections between the path and the boundary) Evolution of Our Positioning Methods
Desire of Fast Tourist LBS Application Generation • Current issues/overhead in development: • Developers are required to put a great effort in the whole development process • Tourist information is usually the main focus • Maintaining the software/information update is difficult also • There is a great desire to have a series of software tools to generate route-based tourist companion software.
Definition – Reference Point • Reference point: Place taken as a reference on target path in the cell data collection process (e.g. bus stop, railway stations)
Definition – Point of Interest • Point of Interest (POI): Location that is interested in the application level (e.g. building, tourist spot)
Software Development Kit • It consists of software tools for: • reducing time spent on tourist LBS application development • providing developers with maximum convenience • Components include: • Cell Snap – cell data collection • Cell Analyzer – cell data processing • Distance Mapper – nearest cell searching • AppGen – tourist LBS application generation
Cell Data Collection and Processing • Data collection has to be done manually • Multiple network operators and routes are involved • Cell data has to be processed and optimized before use • Cell Snap and Cell Analyzer are introduced
Cell Snap • Collection of cell data was done manually in the past • Cell Snap - a tool for automated cell data collection • Different reference points can also be captured by phone camera
Need of Data Processing • Photos and data output are separated, so developers have to map cell data and reference point on their own • Better presentation of cell data to developers • Cell data from multiple telcos have to be combined together • A convenient way to merge data for the same route • Cell Snap data is just raw data • Data editing tool and automated data analysis
Cell Analyzer • Cell Analyzer provides developers with a user-friendly environment to edit, process and aggregate cell data into single master data for further use
Features of Cell Analyzer • It has the following features: • Data processing: • Data format transform • Better cell data presentation to developers • Manual cell data editing • Data combination for multiple operators • Automated data optimization: • Cell duplicate removal • Clear classification between reference points
Location-to-cell Mapping • Up to now, pure cell data are not mapped to geometrical locations • It is quite impressive to have “nearest target” searching functions inside tourist companion mobile application, such as: • Restaurant • Toilet • ATM • Hospital / Police Station • ……
Distance Mapper • Distance Mapper lets developers to map those POIs onto a real map • The tourist application is then allowed to search the nearesttarget from currentlocation • It reads in the filegenerated byCell Analyzer
Application Generation • The previous tools mentioned enable developers to have a nice tourist LBS application development environment • LBS application often focuses also on content and service, including actions upon cell changes and information provided • Points of interest (e.g. tourist spots) should also be considered instead of just reference points (e.g. bus stops)
AppGen • AppGen is specifically designed for content builders by generating source code for a tourist LBS application • General developers may also use source code as a starting point to build their own applications
Options Provided in AppGen • General • Map displayed • Icon • Message format • Reference Point • Location on the map • Point of Interest • Name • Description • Image • Path to POI from a reference point
Generated Mobile Tourist Companion Software • The mobile tourist application generated would be able to: • keep track of interested cell changes and report to user (e.g. entering a new MTR station) • let user specify a POI (e.g. Engineering Building in CUHK) and acknowledge user when he/she arrives a reference point containing that POI (e.g. bus stop)
Application in Action (1) Points of Interest Reference Points
Application in Action (2) 1. User selects adestination
Application in Action (3) 2. User is at the startingpoint of a route
Application in Action (4) 3. The application keepstrack of the location of theuser in the path at eachreference point
Application in Action (5) 4. Display the informationabout the point of interestwhen the user arrives thedestination reference point