diff -r 51a74ef9ed63 -r ae94777fff8f Symbian3/SDK/Source/GUID-BA49FDC0-808B-5E05-81AC-98637214F304.dita --- a/Symbian3/SDK/Source/GUID-BA49FDC0-808B-5E05-81AC-98637214F304.dita Wed Mar 31 11:11:55 2010 +0100 +++ b/Symbian3/SDK/Source/GUID-BA49FDC0-808B-5E05-81AC-98637214F304.dita Fri Jun 11 12:39:03 2010 +0100 @@ -1,72 +1,72 @@ - - - - - -LBS -Quick StartLocation Based Services (LBS) provides location information for -installed applications and for remote services via a network. Location information -can be used for location stamping artefacts such as photographs and memos, -finding nearby services and facilities, navigation, and the ability for remote -parties to discover the user's whereabouts. -

Location-based services (LBS) use coordinates from the World Geodetic System -(WGS 84), which is also used as a reference system by the Global Positioning -System (GPS).

-

The coordinates are based on values for latitude, longitude, and altitude -(elevation above sea level).

-

The North Pole is 90 degrees North (+90 degrees) and the South Pole is -90 degrees South (-90 degrees). The Equator is defined as 0 degrees; locations -above it have positive latitudes (0 to +90 degrees); those below (0 to -90 -degrees) negative ones.

-

There are two definitions of North Pole; Magnetic North Pole and True (Geographical) -North Pole. Any application with a compass must check how the API defines -North Pole.

-

The Magnetic North Pole is the point to which compasses point. The True -North Pole defines latitude as +90 degrees.

-

Meridians are constant longitudinal (north-south) values. The Prime (Greenwich) -Meridian’s value is 0 degrees. WGS84, which LBS use, defines its zero meridian -some 100 meters east of the Prime one. Locations east of the Prime Meridian -have positive longitudinal values (0 to +180 degrees), those west (0 to -180 -degrees) have negative ones.

-

As seen in the figure below, latitude lines are smaller near the poles. -At the equator, one degree of longitude is roughly 111.3 km, whereas at 60 -degrees of latitude one degree of longitude is only 55.8 km, which is more -difficult to see.

- - - -
Getting started -with LBS

This section provides links to the most important documentation.

For -application developers

The Location -Acquisition API is the interface that programmers use to create location-aware -applications. The API gives developers the ability to get location fixes and -to obtain information about the positioning technologies available to the -mobile device.

- -
Technologies

The -main technologies enabled on the Symbian platform by the LBS subsystem are -as follows:

    -
  • Global Positioning System -(GPS)

    The GPS system provides accurate, worldwide positioning. The -main disadvantage of GPS is the long time required to obtain a position fix -when the GPS hardware is first powered. LBS supports Assisted GPS (A-GPS) -to reduce the time required to get a position fix.

  • -
  • Network based positioning

    Network -based positioning is typically less accurate than GPS, but often provides -a faster fix of adequate accuracy for some applications.

  • -
  • Secure User Plane Location -(SUPL) v1.0

    SUPL defines an architecture for supporting Location Based -Services using IP bearers to connect handsets and network hosts. The Symbian -LBS subsystem contains a SUPL Protocol Module to support SUPL.

  • -
- -

The above figure illustrates how the location information can be -provided to the device. Access to these location methods is provided through -the positioning modules.

+ + + + + +LBS +Quick StartLocation Based Services (LBS) provides location information for +installed applications and for remote services via a network. Location information +can be used for location stamping artefacts such as photographs and memos, +finding nearby services and facilities, navigation, and the ability for remote +parties to discover the user's whereabouts. +

Location-based services (LBS) use coordinates from the World Geodetic System +(WGS 84), which is also used as a reference system by the Global Positioning +System (GPS).

+

The coordinates are based on values for latitude, longitude, and altitude +(elevation above sea level).

+

The North Pole is 90 degrees North (+90 degrees) and the South Pole is +90 degrees South (-90 degrees). The Equator is defined as 0 degrees; locations +above it have positive latitudes (0 to +90 degrees); those below (0 to -90 +degrees) negative ones.

+

There are two definitions of North Pole; Magnetic North Pole and True (Geographical) +North Pole. Any application with a compass must check how the API defines +North Pole.

+

The Magnetic North Pole is the point to which compasses point. The True +North Pole defines latitude as +90 degrees.

+

Meridians are constant longitudinal (north-south) values. The Prime (Greenwich) +Meridian’s value is 0 degrees. WGS84, which LBS use, defines its zero meridian +some 100 meters east of the Prime one. Locations east of the Prime Meridian +have positive longitudinal values (0 to +180 degrees), those west (0 to -180 +degrees) have negative ones.

+

As seen in the figure below, latitude lines are smaller near the poles. +At the equator, one degree of longitude is roughly 111.3 km, whereas at 60 +degrees of latitude one degree of longitude is only 55.8 km, which is more +difficult to see.

+ + + +
Getting started +with LBS

This section provides links to the most important documentation.

For +application developers

The Location +Acquisition API is the interface that programmers use to create location-aware +applications. The API gives developers the ability to get location fixes and +to obtain information about the positioning technologies available to the +mobile device.

+ +
Technologies

The +main technologies enabled on the Symbian platform by the LBS subsystem are +as follows:

    +
  • Global Positioning System +(GPS)

    The GPS system provides accurate, worldwide positioning. The +main disadvantage of GPS is the long time required to obtain a position fix +when the GPS hardware is first powered. LBS supports Assisted GPS (A-GPS) +to reduce the time required to get a position fix.

  • +
  • Network based positioning

    Network +based positioning is typically less accurate than GPS, but often provides +a faster fix of adequate accuracy for some applications.

  • +
  • Secure User Plane Location +(SUPL) v1.0

    SUPL defines an architecture for supporting Location Based +Services using IP bearers to connect handsets and network hosts. The Symbian +LBS subsystem contains a SUPL Protocol Module to support SUPL.

  • +
+ +

The above figure illustrates how the location information can be +provided to the device. Access to these location methods is provided through +the positioning modules.

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