What is ADS-L, and how does it differ from ADS-B?
ADS-L stands for "Automatic Dependent Surveillance - Light". It is a protocol designed to enable low-cost, low-power devices to transmit position and other data, enhancing situational awareness and safety in aviation. ADS-L is distinct from ADS-B, but compatible in terms of parameter definitions. (e.g. B for broadcast has been deliberately omitted in anticipation of the possibility of network communications). The "light" in ADS-L refers to the use of low-power, low-cost devices, making it an attractive solution for general aviation, and other aircraft not equipped with certified ADS-B installations. ADS-L transmission is not intended to provide any credit during IFR operations except enhancing pilots’ situational awareness.
Why is ADS-L needed and what benefit does it bring?
Many aircraft, especially in general aviation, are not equipped with certified ADS-B installations. ADS-L provides a unified, cost-effective and easy-to-implement solution for these aircraft to enhance their situational awareness and safety. By using ADS-L, aircraft can be visible to other ADS-L equipped aircraft, reducing the risk of collisions and improving overall safety.
What are the transmission links supported by ADS-L?
ADS-L is a protocol that can be transmitted over different links. A standard for ADS-L messages over the SRD860 frequency band is already available. Future specifications will follow to enable ADS-L to be transmitted over mobile networks such as 4G and 5G.