Modems including GPS


I am planning to by a GPS enabled wavecom module and its starter kit

is GPS in those modules serve enough quality? I mean precise in coordinates and receiving ability in low signal strength. Are these GPSs reliable as the discrete ones?



Q2501 includes an ANTARIS GPS Engine. You can see the main parameters on this site:

As you can see its sensitivity is about -150 dbm, so sensitivity is far away from a SirfIII based receiver (-159 dbm).
You can’t expect much from it, but with a well placed and good gps antenna it works well.

best Regards,


q2501B includes a RTC, Does placing a 3V backup battery in my design helps in GPS start time?

Thanks in advance


The RTC helps the receiver to reserve the GPS sat information (ephimeris, almanac, time) when the reciever has no power supply. If this data is not too old (app. less than 6 hours) the receiver can produce a hot or warm start, which are faster then the normal cold start.

Bye the way, it is common thumb of rule using the GPS RTC in every GPS application if possible.

Best Regards,