ZED-F9H - Integration manual
receiver is restarted. For more information, see the description of the UBX-UPD-SOS messages
in the applicable interface description [
3.9.4 AssistNow Online
AssistNow Online is u-blox's end-to-end Assisted GNSS (A-GNSS) solution for receivers that have
access to the internet. Data supplied by the AssistNow Online Service can be directly uploaded to
the receiver in order to substantially reduce time to first fix (TTFF), even under poor signal conditions
(typically around 2 seconds; see the applicable data sheet [
] "Aided start"). The system works
by collecting data such as ephemeris and almanac from the satellites through u-blox's "Global
Reference Network" of receivers and providing this data to customers in a convenient form that can
be forwarded directly to u-blox receivers.
The AssistNow Online Service uses an HTTP interface. Therefore, it works on all standard mobile
communication networks that support internet access, including GPRS, UMTS and Wireless LAN.
No special arrangements are needed with mobile network operators to enable AssistNow Online.
Figure 22: MGA architecture
The data returned by the AssistNow Online Service is a sequence of UBX-MGA messages, starting
with an estimate of the current time in the form of a UBX-MGA-INI-TIME_UTC message.
AssistNow Online supports GPS, GLONASS, BeiDou, Galileo, and QZSS.
Customers may choose to use third party sources of assistance data instead of using
the AssistNow Online Service. Customers choosing this option will need to ensure that
the data is converted from the format used by the third party source to the appropriate
MGA messages. However, it is important to ensure that the receiver has an estimate of the
current time before it processes any other assistance data. For this reason, it is strongly
recommended to send a UBX-MGA-INITIME_UTC or UBX-MGA-INI-TIME_GNSS as the first
message of any assistance.
3.9.4.1 Host software
As u-blox receivers have no means to connect directly with the internet, the AssistNow Online
system can only work if the host system that contains the receiver can connect to the internet,
download the data from the AssistNow Online Service and forward it on to the receiver. In the
UBX-19030120 - R04
3 Receiver functionality
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