• SJU reference # PJ.14-W2-84d /Release 10
  • Stakeholders
  • Benefits Cost-efficiency
  • Status In the pipeline


This Solution was formerly  part of PJ.14-04-03-W1

Implementation of a wide range of surveillance technologies, including ADS-B, impacts data transmission. This candidate solution addresses the future ADS-B communications link, in particular phase overlay for Mode S and ADS-B datalink.

SESAR 2020 is using phase overlay techniques, which consists of overlaying phase-shift keying (PSK) onto the pulse position modulation (PPM) messages to carry separated information, avoiding the need to modify the structure of the current extended squitter message or assigned spectrum. The extended number of bits in a phase overlay message allows additional data to be transmitted. This new extended data could be used to provide new types of information or complement current ADS-B PPM message. Also, Phase overlay technology opens the possibility for future applications. This data received in ADS-B messages, could improve aircraft situational awareness (e.g. providing weather information). It could allow aircraft to better understand the environment, making appropriate decisions during the flight, increasing safety and reducing the risk of accidents. Additional data could also be used to secure ADS-B transmission avoiding threats as spoofing and eavesdropping. Finally, this higher rate of bit transmission could also be useful for V2V transmission in UAM environment. All these possibilities could be studied in future SESAR research projects.

Specifically, during Wave 2, PJ14-W2-84d aims to significantly improve the transmitted bit rate, increasing the data transmission from 112 to 448 bits (from 56 to 204 useful bits). The Candidate solution will validate the waveform and performances required for the phase overlay transmitter and receiver currently standardised on ED-102B / DO-260C and ED-73F / DO-181F and contribute to ongoing standardisation activities by RTCA SC-186 and SC-209, and EUROCAE WG-51, by providing feedback on the results of the candidate solution.


 Cost efficiency in terms of technology cost per flight