There are two primary methods of time dissemination around the world: two-way satellite time transfer_(TWSTT) and common-view Global Position System_(GPS) time transfer.

Time transfer by laser pulses is based on the propagation of light pulses between satellite and ground clocks or between remote clocks on THC Earth.

With the demand of time synchronization between ground stations of satellite navigation system, the traditional time transfer methods are summarized systematically.