Increased capacity in ADS-B messages implementing Phase Shift Keying encoding

This paper provides a detailed overview of the Phase Shift Keying (PSK) modulation applied as a new Automatic Dependent Surveillance – Broadcast (ADS-B) feature introduced in the last normative documents DO-260C / ED-102B, developed within the Single European Sky Air Traffic Management (ATM) Research (SESAR) 2020 PJ.14-W2-84d solution. An explanation of the technology, along with objectives, validation exercises, results, conclusions, benefits and recommendations based on the performed work is given.PJ.14-W2-84d was a technological solution validating the new PSK feature for ADS-B, which enables the transmission of additional information through the phase modulation of the current amplitude Pulse Position Modulation (PPM) of ADS-B. This modification avoids the need to change the structure of the current extended squitter message of its assigned spectrum (1090 MHz), maintaining the backwards compatibility of the ADS-B surveillance system.The improvement of this ADS-B version on the transmission bit rate (data rate increases from 112 to 448 raw bits, effectively from 56 to 260) will allow the transference of new data, which could be used for diverse applications: provision of a more detailed weather information, authentication of ADS-B transmissions in order to avoid threats as spoofing, or reduction of the 1090 MHz frequency spectrum congestion, among others. To achieve its targets, the solution followed the specifications of the RTCA and EUROCAE published standards: DO-260C and ED-102B, respectively.This solution was part of research activities carried out within the frame of SESAR 2020 PJ.14-W2 I-CNSS project. This project aimed to develop an integrated suite of CNS solutions meeting the current and future operational requirements of air traffic management in the short, mid and long term. This includes a strengthened security and increased spectrum efficiency. In addition, it aims to ensure their global interoperability, as outlined in the International Civil Aviation Organization (ICAO) Global Air Navigation Plan (GANP).The PJ.14-W2 I-CNSS project aimed to support European and global harmonization of CNS between airlines, Air Navigation Service Providers (ANSP) and industry, as well as interoperability between civil and military aviation.Continuing with the outcomes obtained in this solution and shown in this paper, a new SESAR 3 solution has been created within MITRANO project to study the potential introduction of an authentication algorithm for ADS-B in order to avoid threats such as spoofing. This solution will study if the implementation of this new feature making use of the extra data capacity provided by Phase Shift Keying is feasible, which would provide an additional security layer to ADS-B surveillance system.