As of today, Unmanned Aerial Vehicles (UAV) fly exclusively in segregated airspace. Their communication link encompasses both Payload data and Command & Control flows. When beyond the radio line-of-sight, they use mainly Ku-band satellite communications, often through commercial satellites, which are utilized thanks to transponder lease schemes. When under radio line-of-sight conditions, they rely on a wide range of solutions, mainly in C, Ku, S and UHF bands.
In the near future, all civil and military UAV applications will require access to non-segregated airspace at some point in the flight pattern. A seamless integration into air traffic system with an equivalent level of safety as a manned aircraft must be achieved. A key driver is the ability to ensure safe and secure communications between the Unmanned Aircraft Control Station (UACS) and the UAV. ICAO (International Civil Aviation Organisation) recommends, for these communications, the use of aeronautical safety spectrum, acknowledging how crucial they are for the safe integration of UAV within non-segregated airspace.
Figure: Segregated airspace versus non-segregated airspace
The next World Radio Conference 2012 (WRC-2012) will have to decide on the identification of globally harmonized spectrum for UAS safe operation in non-segregated airspace. To accomplish this, in the frame of ITU (International Telecommunications Union) discussions for WRC-2012 preparation, various regulatory methods are envisaged and will be analyzed in the frame of ESPRIT project, each one corresponding to a different alternative in terms of system solution. ESPRIT project objectives can be summarized as follows:
The Key issues at stake in the frame of this project are the following:
ESPRIT project key benefits will be the following
The preliminary architecture presented below provides an initial baseline that will have to be refined in the frame of ESPRIT project.
The UACS (UA Control Stations) are connected to a satellite communications system. Each UACS is able to command and control one or various UAV. The UACS are supposed to be outside the communication system.
This system should be compatible with very stringent availability requirements and should be able to offer a high capacity.
Finally, depending on the frequency allocation finally chosen, the solution could provide a global and unified Command & Control capability beyond-line-of-sight conditions and, thus, offer, through a single piece of equipment, a universal access to all civil airspaces worldwide.
During the 9-month project duration the following plan will be implemented in order to fulfill the objectives of the project:
The project has been finalised.