Is it what they call 'free flight'?

Yes, I believe it is or is similar. Standard airline routes tend to bunch planes into airways that go from one ground-based navigation station to another. This increases the distance between points because airways go between the navigation stations instead of the airports. It also tends to bunch planes together.

The free flight concept allows planes to fly more direct routes between takeoffs and landings, reducing both distance flown and congestion. ADS-B reverses how air traffic control (ATC) is done. Currently, ATC uses ground-based radars to track planes and determine their position. It also uses a device called a transponder to positively identify the planes (via an assigned identifier code) and to determine the plane's altitude. These ATC radars cost a lot of money to install and operate. I've heard the cost could be over a million dollars a year per radar.

Instead of radars, ADS-B uses GPS data. The planes transmit their altitude and position (and maybe course info) on a regular basis to simple and inexpensive ground receivers. Planes with advanced equipment can also receive the ADS-B transmissions from other planes, allowing the planes to work out their own separation. It may sound like chaos but it works very well. The ADS-B ground receivers can be located in places that wouldn't be suitable for ATC radars, such as the tops of mountains. This can greatly improve coverage in mountainous terrain. I've also read that properly equipped planes can receive additional data via an uplink for things such as weather information.

The FAA is moving to require ADS-B equipment in nearly all planes by 2016 or so. There is a concern about how much the equipment will cost. If it's $1000-2000 per plane, it'll be rapidly adopted. The last number I heard was over $6000 per plane and that may not even count installation costs. That's a lot harder for people like me who fly older planes that might not be cost effective to upgrade.

ADS-B is a wonderful invention. It's already in use in some places and is well on it's way to becoming the new international standard for ATC. However, like everything else involving aircraft, it isn't cheap. The only thing cheap about an airplane is the air in the tires. I paid almost $30 this week for a [profanity deleted] air filter and $16 each for spark plugs.

ADS-B: Will It Be Filled In?


UPS Pioneers ADS-B

Airport radar soon a blip in history