L-Band Digital Aeronautical Communications System or LDACS is an air/ground secure communication technology that also has navigation and surveillance capabilities. It is one of the options being considered in the EU to enhance the current and future mobile data link applications as part of the Future Communications Infrastructure (FCI).
EUROCONTROL and SESAR recently hosted a webinar with industry experts from EUROCONTROL, IATA, ICAO, SESAR Joint Undertaking and the FAA to discuss the current status and possible future implementation of LDACS.
Let’s start with the why? As aviation increasingly becomes more of a machine-to-machine series of communications, there is a need to consider a change in the systems that are currently in use. If you consider the path these communications have taken over the years, we have gone from analog voice only to voice and data to IP. And now IP is being supported with SWIM or Systemwide Information Management. This moves us closer to a high-speed broadband datalink infrastructure where the aircraft is a node on the SWIM network.
SWIM will enable XML-based communications that bring graphics to the cockpit and allow todays ‘connected aircraft’ to also have a ‘connected cockpit’. In order to achieve this, we need to have spectrum-efficient broadband solutions. The amount of mobile wireless spectrum that is currently in use in our industry won’t be increasing in the future. This means that efficiency is key.
In addition to efficiency, security must also be ensured. As we increase automation, while decreasing direct human-to-human interaction, security must be addressed. Aircraft Operations and ATM communications need to remain separate, although the same infrastructure onboard the aircraft needs to be used to support these functions to stay within space and power usage guidelines. Safety and time critical communications need to take priority.
Let’s consider what a few examples of the types of data that would fall into each of these communications categories:
Aircraft Operations data
- Uplink: Flight plans, Weather, Fuel monitoring
- Downlink: Pilot reports, Real-time failures, and warnings
Air Traffic Systems communications
- Reliable QoS is mandatory
- ADS-C, ATIS, Departure clearance
As the number of new aircraft begin to grow within our airspace – RPAS, UTM, UAM and HAPS for example – the safety and security, quality of service discussion becomes more complex. LDACS manages service priorities based on the type of communication. Therefore, bandwidth can be guaranteed along with lower latency transmission of data ensuring safety-critical applications have the highest priority while also accommodating aircraft operations.
This technology is still under consideration, as mentioned above, but certainly seems a viable alternative to secure future automation of aircraft and ANSP communications. Only a few key considerations are highlighted in this article, but I urge you to spend time learning more about this topic through the organisations that joined the webinar mentioned previously.