Originally Posted by
ATC Watcher
My comment was not a speculation but a fact. The South Indian Ocean airpace is not the North Atlantic , and data link processing load is an issue for the Australian system, hence the trial.
But ADS-C (Automatic Dependent Surveilance - Contract) is addressable SATCOM, with up to 5 contracts that can be held concurrently. So you could have a contract with any agency worldwide, including your own dispatch. ADS-C cannot overload the air traffic service provider of the airspace the aircraft is flying in, if they are contracted to receive the ADS-C they merely have to store the data - a short data message every 15 minutes.. The South Indian Ocean Airspace is indeed different to the North Atlantic. It is extremely sparsely flown whereas the North Atlantic is ~2000+ flights a day.