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  (Drawing courtesy if CNS Inc, Springfield VA.)

Figure 2: The First Airborne Internet Proof of Concept Test Bed


The workstation acting as the ground station is the AI router in addition to running applications to support ADS-B, weather and e-mail. This router workstation is connected to the Internet as well as to a ground LAN and to the VDL Mode SATS radio. The Controller Pilot Data Link Communication (CPDLC) ground controller and the peer-to-peer workstations are connected to the ground LAN.

 The web enabled status monitor (located at the Network Operations Center (NOC) in another city) remotely monitors the status of the routers and the radios. A workstation with web browser located in the Springfield facility is used to get the monitor information from the Network Operations Center.

 The test bed has demonstrated the following capabilities:

§       Demonstrate aircraft-to-aircraft communications. A broadcast capability can be achieved using Automatic Dependent Surveillance – Broadcast (ADS-B) and Trajectory Change Point (TCP). ADS-B is a system by which each aircraft’s surveillance transponder is used to broadcast to the other aircraft in the vicinity its position data. ADS-B has also been used to provide the same information to the ground air traffic control system. By using ADS-B, a pilot is provided with the information needed to understand his own “situational awareness” by viewing his own aircraft in the context of those surrounding him. Ships and boats have had  similar “situational awareness” by using shipboard radar in which they can view other vessels (and objects) around them.

§       Ground broadcast Surveillance information service. Traffic Information Services – Broadcast (TIS-B) can be used for this purpose. TIS-B is a system by which air traffic control information available to the air traffic controller is also provided to the aircraft.

§       Maneuver and Control can be demonstrated using Controller Pilot Data Link Communications (CPDLC). This is a system in which ground controllers can issue commands to aircraft using text messaging instead of VHF voice radio. In return, the aircraft can acknowledge on the same text messaging link. The system is being implemented in the NAS today. The purpose of CPDLC is to reduce the usage of the already over subscribed aviation VHF voice radio frequencies. In its simplest form, think of it is an elaborate “Instant Messaging” system.

§       Applicability of external Internet for Flight Information Services – Broadcast (FIS-B) kind of services, such as weather broadcast to aircraft from the ground. E-mail is another important service that can be provided. FIS-B can be used to provide near real time weather information to SATS pilots. One of the uses for VDL Mode SATS is a continuous broadcast by a ground station of local weather conditions or enroute weather.

§       Prove the technology of VHF Digital Link Mode SATS, which uses Self-organizing Time Division Multiple Access (STDMA) as its media access mechanism. VDL Mode SATS permits data communication without the necessity of having a ground station to support the protocol.

§       Peer-to-peer activity between two or more air nodes, and between air and ground nodes. Peer-to-peer communication enables real time collaboration between equal entities by sharing resources and information.

§       Interoperability between applications residing on different platforms.  NEXT

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