A navigation-satellite receiver support data network comprises a server connected
to the Internet to provide initialization information to clients for faster cold
starts. The server includes a GPS receiver that provides for tracking of a constellation
of navigation satellites. When a client is started cold, time and frequency are
initially unknown to it. Test messages are sent back and forth over the Internet
and a path delay time is computed from the average of the quickest transit times.
This yields the offset time between the server's time system and the client's time
system. The server sends current time information to the client, and the computed
path delay is added. The client can then compute correct time from the server and
path delay information, and thereby select much sooner which satellites are correct
to search.