An overview of VHF civil radio network and the resolution of spectrum depletion

The spectral capacity of VHF aeronautical radio is rapidly reaching saturation in the United States and in Europe. A key functional objective for any future civil aviation communications technology is providing relief to the current spectral congestion. This article provides a review on the existing national and global aeronautical radio networks. The spectrum depletion problem is described. Recent developments in narrowband and wideband digital communications for potential applications in civil aviation are discussed. Comments are made on critical issues that must be considered when selecting a communication technology for aeronautics which addresses the spectral congestion problem and simultaneously supports transformation to a long term network centric solution. Recommendations are made on some possible communication technologies that may bring about short-term resolution to VHF spectrum depletion without requiring major changes in ground infrastructure or on-board avionics.