And there is no other ADS-B In system in use in the USA except PowerFLARM that has a PCAS like capability. ADS-B TIS-B that Mike and I have mentioned here several times is more complex and you need to go read about that to understand the limitations of where/when it works. Mike mentioned the limitations already, and I have posted similar comments many times on r.a.s. But again TIS-B is academic if you are using a PowerFLARM receiver, the European folks involved in developing PowerFLARM just did not implement support for it.