L-DACS1 air-to-air data-link protocol design and performance

All advanced concepts of operation in future Air Traffic Management (ATM) assume that digital air/ground and air/air links are available. Seeking to define a future communication system suitable for planned air-to-air and air-to-ground ATM operations, the Federal Aviation Administration (FAA) and EUROCONTROL initiated a joint study in the frame of Action Plan 17 (AP17) to investigate suitable technologies and provide recommendations to the ICAO ACP Working Group T. Two proposals for the L-band Digital Aeronautical Communication System (L-DACS) were elaborated. This paper discusses the L-DACS1 proposal, a multi-application broadband system capable of simultaneously supporting various kinds of air-to-air and air-to-ground Air Traffic Services (ATS) and Airline Operational Communications (AOC) data link services. This paper presents the research towards the design and the performance evaluation of the proposed medium access control sub-layer and logical link control sublayer of the L-DACS1 air-to-air protocol stack. The L-DACS1 air-to-air protocol has been designed for the periodic transmission of air-to-air surveillance data while supporting the transmission of a low volume of non-periodic addressed air-to-air messages. It tries to achieve this objective via a self-adaptive slotted TDMA protocol.