The ADS-B requirement is merely 6+ years away. Consider
that when you make any avionics replacement/addition
decisions.
1. ADS-B Out will be required where Mode-C transponders are
now required.
2. ADS-B Out can be achieved by either Extended
Squitter (ES) sent out at the transponder frequency (1090 MHz)
or by a transceiver at 978 MHz.
3. If you fly above FL18, you must at least transmit ADS-B
Out on the 1090 MHz frequency (ES).
4. The Out signal info must have the location/speed
data derived from an approved WAAS GPS.
5. The ground stations will transmit weather data
(FIS-B) and all collected position information (however
collected) on the transceiver frequency of 978. 1090 is just
too overloaded. The traffic data (TIS-B) is limited to a
hockey puck shaped space around the aircraft that is
transmitting its position (thousands of feet thick and 30 NM
diameter ?). Thus, if you are not transmitting your own
position (ES or transceiver with WAAS data), you can only pick
up traffic that was generated for airplanes that were
transmitting and your impinging traffic info may not be the
complete picture if you are near the edge of somebody else's
puck.
6. The best transceivers will be dual frequency and receive
data from other aircraft (either 1090 or 978) and the ground
stations (978).
7. Transponder/navigation equipment like the Garmin 430/530
and GTx330 can display only limited weather and traffic info.
The FAA doesn't care what is used to display received
traffic/weather info. I.E. see
http://skyvisionxtreme.com/ and
others (Dynon, etc.).
8. About 525 of the final configuration of 800 ground
station transmitters are operational now and the rest should
be operational by the end of this year (or so). Thus, all the
benefits are achievable now over most of the country. See
http://www.faa.gov/nextgen/flashMap/index.cfm and
click on BEGIN and then ADS-B.
Don't cheap out! Do your research.
Scott Krueger
PS With onboard weather, pilots will choose the
flexibility of VFR flights and the traffic around storms will
be in more congested corridors.
PPS Checking on whether Drones, UAVs and military traffic
will be Outing via ADS-B.