Lock onto your position instantly with AssistNow

Adverse GPS conditions: urban canyonGPS users expect instant position information. With standard GPS this is often not possible because at least four satellites must be identified, and their complete orbital position data, called Ephemeris, received. Under adverse signal conditions, data downloads from the satellites to the receiver can take minutes, hours or even fail altogether.

Assisted GPS (A-GPS) accelerates calculation of position by delivering satellite data such as Ephemeris, Almanac, accurate time and satellite status to the GPS receiver via wireless networks or the Internet. This aiding data enables a GPS receiver to compute a position within seconds, even under poor signal conditions.

u-blox’ reliable AssistNow service is available in Online and Offline versions which can be used alone or in combination. Available to all u-blox OEM customers and their end-users,  AssistNow requires no additional hardware and generates virtually no CPU load. The system is very easy to integrate: Customers can install it and be operational within a day:

  • AssistNow Online: up-to-date satellite information is automatically downloaded
    on each AssistNowdevice start-up to allow instantaneous calculation of your position (TTTF less than 1 second). Size of downloaded data: 1-3 KB.
  • AssistNow Offline: up-to-date satellite information is downloaded once every 14 days. Ephemeris data plus ublox’ “AlmanacPlus” differential correctional data then provide fast and accurate positional calculation for up to 2 weeks without a network connection, and in near real-time (as low as 5 seconds).
 Download AssistNow Product Summary (PDF)  


u-blox products compatible with AssistNow:
For further information:


New products