IOCTL_GPS_WRITE_ASSISTED
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4/8/2010
This IOCTL can be implemented by GPS hardware manufacturers to obtain data used by the GPS hardware to more quickly obtain a GPS fix. For example, GPS hardware in a mobile phone may have the ability to more quickly obtain a GPS fix using information about the current mobile phone tower(s) used by a phone. Applications can provide this data to the GPS hardware using this IOCTL.
An application can use this IOCTL to provide information it previously retrieved, using IOCTL_GPS_READ_ASSISTED.
For more information about how to use and implement this IOCTL, see Implementing GPS Intermediate Driver Hardware IOCTLs.
Note
Almanac data that can be used to enable faster GPS fixes should be provided using IOCTL_GPS_WRITE_ALMANAC.
Parameters
Applications using the GPS Intermediate Driver should use the lpInBuffer parameter of the DeviceIOControl function to pass a pointer to a buffer that contains data previously retrieved using IOCTL_GPS_READ_ASSISTED.
GPS hardware manufacturers that implement this IOCTL can use the lpInBuffer data to attempt to make a GPS fix more quickly.
It is important to note that this data is only meaningful to the GPS hardware. The data is completely opaque to an application using the GPS Intermediate Driver. The degree to which applications can interact with this information is limited to saving the results of IOCTL_GPS_READ_ASSISTED and then providing the saved results to the GPS hardware using IOCTL_GPS_WRITE_ASSISTED.
Return Values
GPS hardware manufacturers may return TRUE if the hardware device driver was able to use the provided data for initialization, and FALSE otherwise. However, this is not required and applications should not rely on the return value obtained when using this IOCTL.
Requirements
| Header | gpsdev.h |
| Windows Embedded CE | Windows Embedded CE 6.0 and later |
| Windows Mobile | Windows Mobile Version 5.0 and later |
See Also
Reference
GPS Intermediate Driver IOCTLs
IOCTL_GPS_READ_ASSISTED
IOCTL_GPS_WRITE_ALMANAC
Concepts
Implementing GPS Intermediate Driver Hardware IOCTLs