Since about 1998 the airlines have introduced FANS on the California / Sydney direct route.
System which is based on Flextrack routes. It is available for B747.400 planes or similar which are fitted with satellite communications as well as the usual HF radio system. Satellite communications allow real time continuous position reports via an automatic data link, which then allow planes to be tracked more accurately at the ground control centres. Planes with only HF can not use this system due to the lower accuracy of HF broadcasts due static etc.
Flextrack routes are the previous non-stop routes with daily amendments due to weather changes. This allows route changes to take advantage of wind forecasts etc. that results in lower fuel costs.