Publisher : National Aeronautics ad Space Admiinistration 

Title : Reliable, Secure, and Scalable Communications, Navigation, and Surveillance (CNS) Options for Urban Air Mobility (UAM)

Publication Year : 2020

Download Link : https://ntrs.nasa.gov/api/citations/20205006661/downloads/UAM%20CNS%20Final%20Report%2080GRC019D0017%20with%20App%20A%20B%20C%20v2.pdf