A communication device within a GNSS group propagates GNSS assistance data to one or more other communication devices in the GNSS group utilizing direct device-to-device connections. The GNSS assistance data comprises ephemeris received from one or more GNSS satellites and/or predicted ephemeris. As a source device, the communication device generates, and/or acquires from other resources such as a remote location server, the predicted ephemeris. As a destination device, the communication device receives existing GNSS assistance data from a source device and/or other communication devices in the GNSS group. A GNSS position for the communication device and corresponding time information are used to refresh the received GNSS assistance data. In instances where the communication device further acts as a relay device, the refreshed GNSS assistance data is relayed to other communication devices over wired and/or wireless direct device-to-device connections utilizing appropriate communication technologies such as WiFi, Bluetooth and/or Bluetooth low energy.