LDACS Digital Voice – Concept and Expected Performance

Abstract

With a total of 38.3million aircraft departures [1] 2019 was the year with the most flight movements worldwide. After a steep decline in flight movements during the COVID-19 pandemic, recent reports from IATA suggest that the cargo sector has fully recovered, whereas the passenger sector may take longer [2]. At that time, the current air traffic management infrastructure will again reach its limits due to the VHF band saturation and lack of digitalization. In Europe these challenges are investigated within the SESAR program. The introduction of new broadband aeronautical data-links is a cornerstone of the envisaged solution. The terrestrial data link that will be introduced, is the L-band Digital Aeronautical Communication System (LDACS). LDACS is already a mature technology for data transmission: It has been designed [3] based on the quantitative guidance of computer simulations [4], and demonstrated in flight trials [5]. However, LDACS digital voice has not been fully developed, yet. SESAR Project 33 will therefore address the development of LDACS digital voice. The existing LDACS architecture will be enhanced to allow support of digital voice services. Based on this architecture, LDACS prototypes will be implemented and tested. The objective of this paper is to present the proposed LDACS digital voice concept and validate it in computer simulations. Representative evaluation scenarios are defined to analyze the expected performance of the LDACS voice protocol. The results of these computer simulations will assist the protocol design and hardware implementation by providing relevant performance metrics during the design process. Additionally, this also provides quantitative guidance of the expected protocol performance for the technical evaluation in the lab.