Study on CNS Frequency Compatibility in the L-Band

With the growing volume of air traffic and the emergence of new airspace usage, the aeronautical frequency band has become increasingly congested. To alleviate overload of the VHF band, LDACS—a next-generation air–ground communication system using the L-band — is being standardized.

However, as the L-band is already used by critical systems such as SSR and DME, interference prevention presents another major challenge. This study explores the conditions ensuring safe and efficient frequency compatibility in the aeronautical L-band and investigates technologies for effective use of the L-band.