EPO (Extended Prediction Orbit) is one of MediaTek's innovations. It is an off-line server-based Assisted

GPS (A- GPS) solution. EPO is the world's leading technology on the satellite orbit prediction that
supports the orbit prediction for up to 14 days. At this time, this is one of best ways to have the
ephemeris and almanac data available for positioning before receiving the broadcast data, ie, the
EPO can replace the broadcast ephemeris/almanac data. With this information, the receiver can
estimate the satellite location without decoding the data. Therefore, it significantly improves the TTFF
performance, especially for the cold and warm starts.
The architecture layout of the EPO is shown in Figure 1. There are two types of EPO files, EPO and QEPO,
provided by the EPO server. EPO supports the orbit prediction for up to 14 days, which provides the GPS
and GLONASS constellations. After SDK 1.4.0 version, the FW supports Galileo EPO data which is up to
7-day prediction.

After SDK1.5.0 version, the FW supports Beidou EPO data which is up to 3-day prediction. In addition, we
do not support the mode of Beidou EPO used only. In order to facilitate the receiver's performance, it needs
to be downloaded with other constellations' EPO data, eg, GPS and/or GLONASS EPO data. For those
3-day or 7-day EPO data, the corresponding files are uploaded to the server daily. QEPO provides a 6-hour
orbit prediction. The QEPO file is generated on the server every hour. Thus, the valid time of downloaded
QEPO file is always greater than 5 hours. The QEPO supports four constellations: GPS; GLONASS; Beidou;
and Galileo. Users can download the EPO or QEPO file via the internet to their desired devices.

EPO user guide
EPO Implement Demo Code