CSMA versus prioritized CSMA for air-traffic-control improvement

OPNET version 7.0 simulations are presented involving an important application of the aeronautical telecommunications network (ATN), controller pilot data link communications (CPDLC) over the VHF data link mode 2 (VDL-2). Communication is modeled for essentially all incoming and outgoing nonstop air-traffic for just three United States cities: Cleveland, Cincinnati, and Detroit. There are 32 airports in the simulation, 29 of which are either sources or destinations for the air-traffic of the aforementioned three airports. The simulation involves 111 air traffic control (ATC) ground stations, and 1,235 equally equipped aircraft-taking off, flying realistic free-flight trajectories, and landing in a 24 hr period. Collisionless, prioritized carrier sense multiple access (CSMA) is successfully tested and compared with the traditional CSMA typically associated with VDL-2. The performance measures include latency, throughput, and packet loss. As expected, prioritized CSMA is much quicker and more efficient than traditional CSMA. These simulation results show the potency of prioritized CSMA for implementing low latency, high throughput and efficient connectivity.