A-GPS stands for Assisted GPS. This widely used technology involves providing additional data to the GNSS receiver by an alternative means of communication (e.g., via IP, or by manual data entry), thereby reducing the time for the receiver to acquire and track the actual satellite signals. This may lead to a significantly shorter time for NetClock to deliver a GNSS-based timing signal upon a “cold start” of the unit.
The A-GPS client is used to send assistance data to the GPS receiver. This is most useful in areas with poor GPS reception.
The A-GPS client functionality is only available with the following GNSS receiver models:
- Res-SMT GG
- u-blox M8T
An A-GNSS server allows a NetClock unit to operate as a server, thus providing A-GNSS ephemeris and almanac data to other client devices e.g., a Spectracom GSG-series GNSS simulator.
The A-GNSS functionality largely depends on the GNSS receiver model installed in your unit:
- Res-SMT GG: Produces server files only for GPS
- u-blox M8T: Produces server files for GPS, BeiDou, Galileo Rinex3 and Almanac
Caution: Do NOT use GLONASS when operating NetClock as an A-GNSS server, since this will likely crash the A-GNSS software.
To determine which GNSS receiver model is installed in your NetClock unit, see Determining Your GNSS Receiver Model.