Master

'

s Thesis 2006 

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STUTTGART

TECHNIK

Conclusion 

        STUTTGART UNIVERSITY OF APPLIED 

SCIENCES 

For LBS function developing, the client can use the Location API for J2ME (JSR 179), 

a set of generic APIs that can be used for developing location based services. This 

API defines an optional package, 

javax.microedition.location

, which enables 

developers to write wireless location based applications and services for 

resource limited devices like mobile phones, and provides mobile applications with 

information about the device s present physical location and orientation (compass 

direction), and support the creation and use of databases of known landmarks, stored 

in the device.   

For Location API and GPS receiver, location can be expressed in the widely used 

latitude longitude altitude

 coordinate system. Latitude is expressed as 0 90 degrees 

north or south of the equator, and longitude as 0 180 degrees east or west of the prime 

meridian, which passes through Greenwich, England. Altitude is expressed in meters 

above sea level. 

After got the coordinate of one location, if we want to display the location on the map 

in client, the 

latitude longitude altitude

 coordinate should be converted to North East 

(X,Y) Coordinates, such as UTM (Universal Transverse Mercator), using some 

complex calculation coordinate transformation. 

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