I have had a major interest in monitoring ADS-B signals for a number of years now. Longtime readers of the Milcom MP blog know that I post all my mil intercepts daily on here. It is a fascinating part of the mil monitoring hobby.
In the August 2019 TSM Milcom column (available at https://www.thespectrummonitor.com/), I cover the latest info on the January 1, 2020 implementation by the FAA of ADSB Out.
Now RTL-SDR.com has a nice article posted this morning on setting up a remote ADS-B, ACARS, VDL2 and ATC voice monitoring station using a LTE connection at https://www.rtl-sdr.com/a-remote-ads-b-acars-vdl2-and-air-traffic-control-voice-monitoring-station-with-lte-connection/.