Enfora Enabler II-G Assisted GPS Modem Integration Guide data for the entire constellation. This data is around 30 Kbytes and would be valid for up to 48 hours.
If the LTO data file is downloaded every 4 hours, then it would only download about 2 Kbytes of data
or so. It does not download entire 30 Kbyte file every time.
The next section discusses the recommended approach for downloading the file. It is not necessary
for the GPS antenna to have a clear view of the sky in order to operate. The following commands are
used to set the feature:
The following parameters will need to be programmed in order to provide data connection parameters
to the network and location assistance server:
AT+CGDCONT=1,"IP","APN" - Set GPRS connection with Network. APN is provided
by the network operator
AT%CGPCO=1," username,password",0 - Set GPRS username and password, if any
AT$AREG=2 - Automatic GPRS registration
AT$GPSDST=”1.2.3.4”,”5.6.7.8”,1265 - Set the IP addresses and port number of the SUPL
interface
AT$GPSSRC=1270 - Sets the Source Port number for the SUPL interface
AT$LTOFREQ=4 - Defines how often the LTO files are downloaded from
the SUPL interface (4 hours with this setting)
Set one of the following depending on desired operation:
AT$GOPMD=3,1,0 - Sets the GPS operating mode to enhanced autonomous, the fix
mode to one-time fix, and the periodic report interval to 0 (not used in
one-time fix mode)
AT$GOPMD=3,2,0 - Sets the GPS operating mode to enhanced autonomous, the fix
mode to native, and the periodic report interval to 0 (not used in native
fix mode)
AT$GOPMD=3,3,x - Sets the GPS operating mode to enhanced autonomous, the fix
mode to timed interval, and the periodic report interval x to a value
between 2 and 7200.
Set one of the following depending on desired operation:
AT$GPSLCL=0,<msgType> - Turns all local serial port reporting off, <msgType> is
not used
AT$GPSLCL=1,<msgType> - Directs the GPS data of <msgType> over the main
serial port
AT$GPSLCL=2,<msgType> - Directs the GPS data of <msgType> over a serial DUN
connection (PPP) as UDP/IP packets, with UDP-API
header
AT$GPSLCL=5,<msgType> - Directs the GPS data of <msgType> over the second
serial port
AT&W - Writes the settings to non-volatile memory
Upon setting the configuration above, the modem will operate in enhanced autonomous mode and
will stream the selected data over the desired serial interface.
For additional information and details on the different modes of operation, see MLG0208AN001MAN
– Assisted GPS Module Modes of Operation.
MLG0208PB001 44 Version1.01 – 10/3/2006