Integrated navigation and surveillance capability within L-DACS1

New ATM concepts developed in the course of Single European Sky ATM Research (SESAR) Program in Europe and Next Generation Air Transportation System (NextGen) in the USA rely upon powerful mobile aeronautical communications, and at the same time they require reliable and robust solutions for navigation and surveillance. Recent efforts focus on establishing communications services within the navigation bands, in particular in the lower part of the aeronautical L-band (960–1164 MHz). New technologies operating in the same frequency range could use synergies that could not be exploited with “separated” technologies used so far. Following the recommendations of the Future Communications Study, two options for a new L-band Digital Aeronautical Communication System (L-DACS) have been specified: L-DACS1 based on Orthogonal Frequency Division Multiplexing (OFDM) and L-DACS2 based on Time Division Multiple Access (TDMA). Both systems aim at providing high-performance, high-capacity aeronautical communications being deployed in the lower part of the aeronautical L-band (960–1164 MHz). The initial specification of L-DACS1 Air-Ground (A/G) data link [1] is based on the Broadband Aeronautical Multi-carrier Communications (B-AMC) technology that has been complemented by some desirable features of other broadband technologies, primarily TIA-902 (P34) and IEEE 802.16e (WiMAX). Any new communication system in the L-band has to co-exist with the existing L-band navigation and surveillance systems. Moreover, the performance of such a new system is limited by the interference received from existing systems. This paper discusses the motivation and the basic principles of integrating navigation (NAV) and surveillance (SUR) functions within the L-DACS1 communications (COM) system. The detailed concepts for these L-DACS1 functional enhancements are currently being developed in the course of an Austrian research project, called CoLB -Consolidated L-DACS1 based on B-AMC. The proposed concept aims at optionally providing configurable navigation and surveillance services to airspace users along with mandatory communications services. Additional services would be provided in a non-mandatory way, without introducing potentially dangerous coupling of CNS modes within the communications system itself.