Dept of Defense (TSWG) -USAF-FAA (2010) Prepared White Paper on creation of a Virtual Security Simulation Lab (VSSL) to leverage the benefits of virtualization using existing technology such as VMware or Zen and commercial off the shelf (COTS) or other Open Source virtual security appliances, to facilitate the development of cyber security standards for NextGen. Next Generation Air Transportation System (NextGen) is the name given to a new National Airspace System (NAS) due for implementation across the United States in stages between 2012 and 2025. The NextGen proposes to transform America’s air traffic control system from an aging ground-based system to a satellite-based system.